Difference between revisions of "Soft tissue lesions"

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*Once upon a time almost everything was called ''malignant fibrous histiocytoma''; thus, it is listed as a common entity in some publications.
*Once upon a time almost everything was called ''malignant fibrous histiocytoma''; thus, it is listed as a common entity in some publications.


===Most common:<ref name=pmid17976362>{{cite journal |author=Skubitz KM, D'Adamo DR |title=Sarcoma |journal=Mayo Clin. Proc. |volume=82 |issue=11 |pages=1409–32 |year=2007 |month=November |pmid=17976362 |doi= |url= http://www.mayoclinicproceedings.com/content/82/11/1409.long}}</ref>===
Most common:<ref name=pmid17976362>{{cite journal |author=Skubitz KM, D'Adamo DR |title=Sarcoma |journal=Mayo Clin. Proc. |volume=82 |issue=11 |pages=1409–32 |year=2007 |month=November |pmid=17976362 |doi= |url= http://www.mayoclinicproceedings.com/content/82/11/1409.long}}</ref>
*Liposarcoma.
*Liposarcoma.
*Leiomyosarcoma.
*Leiomyosarcoma.
Line 44: Line 44:


==Morphohistologic patterns==
==Morphohistologic patterns==
{{Main|Basics#Morphologic_patterns}}
{{Main|Morphologic patterns}}
{| class="wikitable sortable" style="margin-left:auto;margin-right:auto"
{| class="wikitable sortable" style="margin-left:auto;margin-right:auto"
! Name
! Name
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! DDx
! DDx
! Image(s)
! Image(s)
! Other
|-
|-
| Storiform, [[AKA]] patternless pattern<ref name=pmid9704618>{{cite journal |author=Mangano WE, Cagle PT, Churg A, Vollmer RT, Roggli VL |title=The diagnosis of desmoplastic malignant mesothelioma and its distinction from fibrous pleurisy: a histologic and immunohistochemical analysis of 31 cases including p53 immunostaining |journal=Am. J. Clin. Pathol. |volume=110 |issue=2 |pages=191–9 |year=1998 |month=August |pmid=9704618 |doi= |url=}}</ref>
| Storiform, [[AKA]] patternless pattern<ref name=pmid9704618>{{cite journal |author=Mangano WE, Cagle PT, Churg A, Vollmer RT, Roggli VL |title=The diagnosis of desmoplastic malignant mesothelioma and its distinction from fibrous pleurisy: a histologic and immunohistochemical analysis of 31 cases including p53 immunostaining |journal=Am. J. Clin. Pathol. |volume=110 |issue=2 |pages=191–9 |year=1998 |month=August |pmid=9704618 |doi= |url=}}</ref>
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| [[pleomorphic undifferentiated sarcoma]], [[solitary fibrous tumour]], [[dermatofibrosarcoma protuberans]], [[dermatofibroma]]<ref name=pmid224569>{{cite journal |author=Meister P, Höhne N, Konrad E, Eder M |title=Fibrous histiocytoma: an analysis of the storiform pattern |journal=Virchows Arch A Pathol Anat Histol |volume=383 |issue=1 |pages=31–41 |year=1979 |month=July |pmid=224569 |doi= |url=}}</ref>
| [[pleomorphic undifferentiated sarcoma]], [[solitary fibrous tumour]], [[dermatofibrosarcoma protuberans]], [[dermatofibroma]]<ref name=pmid224569>{{cite journal |author=Meister P, Höhne N, Konrad E, Eder M |title=Fibrous histiocytoma: an analysis of the storiform pattern |journal=Virchows Arch A Pathol Anat Histol |volume=383 |issue=1 |pages=31–41 |year=1979 |month=July |pmid=224569 |doi= |url=}}</ref>
| [[Image:Storiform_pattern_-_intermed_mag.jpg |thumb|center|150px| Patternless pattern. (WC)]]
| [[Image:Storiform_pattern_-_intermed_mag.jpg |thumb|center|150px| Patternless pattern. (WC)]]
| other ?
|-
|-
| Herring bone
| Herring bone
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| [[fibrosarcoma]], [[synovial sarcoma]], [[MPNST]]
| [[fibrosarcoma]], [[synovial sarcoma]], [[MPNST]]
| [[Image:Malignant_peripheral_nerve_sheath_tumour_-_intermed_mag.jpg |thumb|center|150px |Herring bone. (WC)]]  
| [[Image:Malignant_peripheral_nerve_sheath_tumour_-_intermed_mag.jpg |thumb|center|150px |Herring bone. (WC)]]  
| other ?
|-
|-
| Fasicular
| Fascicular
| the long axis of the (spindle) cells are perpendicular to one another in adjacent bundles of cells
| the long axis of the (spindle) cells are perpendicular to one another in adjacent bundles of cells
| [[leiomyoma]], [[leiomyosarcoma]]
| [[leiomyoma]], [[leiomyosarcoma]]
| [[Image:Cutaneous_leiomyosarcoma_-_a_-_intermed_mag.jpg |thumb|center|150px| Fasicular pattern. (WC)]]
| [[Image:Cutaneous_leiomyosarcoma_-_high_mag.jpg |thumb|center|150px| Fascicular pattern. (WC)]]
| other ?
|-
|-
| Biphasic
| Biphasic
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| [[synovial sarcoma]], [[DSRCT]], [[alveolar RMS]]
| [[synovial sarcoma]], [[DSRCT]], [[alveolar RMS]]
| [[Image:Desmoplastic_small_round_cell_tumour_-_high_mag.jpg|thumb|center|150px| DSRCT. (WC)]]
| [[Image:Desmoplastic_small_round_cell_tumour_-_high_mag.jpg|thumb|center|150px| DSRCT. (WC)]]
| other ?
|- <!--
|- <!--
| name ?
| name ?
| description ?
| description ?
| DDx ?
| DDx ?
| image ?
| image ? -->
| other ? -->
|}
|}


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*[[epithelioid sarcoma|'''E'''pitheliod sarcoma]].
*[[epithelioid sarcoma|'''E'''pitheliod sarcoma]].
*[[fibrosarcoma|'''F'''ibrosarcoma]].
*[[fibrosarcoma|'''F'''ibrosarcoma]].
*[[pleomorphic undifferentiated sarcoma|'''M'''alignant fibrous histiocytoma (pleomorphic undifferentiated sarcoma]].
*[[pleomorphic undifferentiated sarcoma|'''M'''alignant fibrous histiocytoma (pleomorphic undifferentiated sarcoma)]].
*[[synovial sarcoma|'''S'''ynovial cell sarcoma]].
*[[synovial sarcoma|'''S'''ynovial cell sarcoma]].


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*[[AKA]] ''Undifferentiated pleomorphic sarcoma'', abbreviated ''UPS''.
*[[AKA]] ''Undifferentiated pleomorphic sarcoma'', abbreviated ''UPS''.
*Previously known as ''malignant fibrous histiocytoma'', abbreviated ''MFH''.<ref>URL: [http://sarcomahelp.org/learning_center/mfh.html http://sarcomahelp.org/learning_center/mfh.html]. Accessed on: 8 April 2011.</ref>
*Previously known as ''malignant fibrous histiocytoma'', abbreviated ''MFH''.<ref>URL: [http://sarcomahelp.org/learning_center/mfh.html http://sarcomahelp.org/learning_center/mfh.html]. Accessed on: 8 April 2011.</ref>
 
{{Main|Pleomorphic undifferentiated sarcoma}}
===General===
*Common sarcoma.
*Usually deep tissue of the trunk and extremities.
*A diagnosis of exclusion<ref name=pmid19671033>{{cite journal |author=Matushansky I, Charytonowicz E, Mills J, Siddiqi S, Hricik T, Cordon-Cardo C |title=MFH classification: differentiating undifferentiated pleomorphic sarcoma in the 21st Century |journal=Expert Rev Anticancer Ther |volume=9 |issue=8 |pages=1135–44 |year=2009 |month=August |pmid=19671033 |pmc=3000413 |doi=10.1586/era.09.76 |url=}}</ref> / wastebasket for unclassifiable high grade sarcomas.
 
===Microscopic===
Features:<ref name=Ref_WMSP_613>{{Ref WMSP|613}}</ref>
*Storiform pattern ([[AKA]] ''patternless pattern'') - '''key feature'''.
*Marked [[nuclear pleomorphism]] '''key feature'''.
**Variation is nuclear size, nuclear shape and nuclear staining (esp. hyperchromasia).
*Mitoses - abundant; atypical mitoses common.
*Necrosis (common).
*Mix of spindle cells and epithelioid cells.
*Deep to skin  - '''important'''.
 
Other findings:
*+/-Giant cells (see subclassification).
*+/-Inflammation (see subclassification).
**Neutrophils.
**Eosinophils.
 
Notes:
*Superficial lesions with the morphology of ''PUS'' are called by some ''[[atypical fibroxanthoma]]s'' (AFXs).
 
DDx:
*[[Atypical fibroxanthoma]] (AFX) - superficial skin.
*[[Dedifferentiated liposarcoma]].
*[[Leiomyosarcoma]].
*[[Metaplastic carcinoma]].
*[[Malignant melanoma]].
*[[Rhabdomyosarcoma]].
*[[Synovial sarcoma]].
*Others.
 
====Images====
<gallery>
Image:Pleomorphic_undifferentiated_sarcoma_-_very_high_mag.jpg | PUS - high mag. (WC/Nephron)
Image:Pleomorphic_undifferentiated_sarcoma_-_intermed_mag.jpg | PUS - intermed. mag. (WC/Nephron)
</gallery>
====Subclassification====
Pleomorphic sarcoma (PS) is subclassified the following way:<ref name=Ref_WMSP_613-4>{{Ref WMSP|613-4}}</ref>
*PS with giant cells.
*PS with inflammation.
*PUS (not otherwise specified) - wastebasket diagnosis; if neither of the above two apply.
 
===IHC===
Exclusionary stains - should be negative:
*AE1/AE3.
*p63.
*Myogenin.
*S-100.
*HMB-45.
 
Usually negative, may be positive:<ref name=Ref_WMSP613>{{Ref WMSP|613}}</ref>
*Desmin.
*SMA.
 
Commonly positive:
*CD68.<ref name=Ref_WMSP613>{{Ref WMSP|613}}</ref>
*Vimentin.


=Fibroblastic/myofibroblastic tumours=
=Fibroblastic/myofibroblastic tumours=
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=Tumours of uncertain differentiation=
=Tumours of uncertain differentiation=
==Angiomatoid fibrous histiocytoma==
==Angiomatoid fibrous histiocytoma==
===General===
{{Main|Angiomatoid fibrous histiocytoma}}
*Rarely metastasizes.
*Children & young adults.
 
===Microscopic===
Features:<ref name=Ref_WMSP624-5>{{Ref WMSP|624-5}}</ref>
*Cystic spaces with blood - simulates a vascular neoplasm.<ref name=pmid228836>{{Cite journal  | last1 = Enzinger | first1 = FM. | title = Angiomatoid malignant fibrous histiocytoma: a distinct fibrohistiocytic tumor of children and young adults simulating a vascular neoplasm. | journal = Cancer | volume = 44 | issue = 6 | pages = 2147-57 | month = Dec | year = 1979 | doi =  | PMID = 228836 }}</ref>
*Epithelioid to spindle cells.
**May have a histiocytic appearance.<ref>URL: [http://dermatology.cdlib.org/1605/1_case_reports/4_09-00041/patrizi.html http://dermatology.cdlib.org/1605/1_case_reports/4_09-00041/patrizi.html]. Accessed on: 15 November 2011.</ref>
*Inflammation.
**Lymphoid cuff<ref name=pmid20154033/> - lymphocytes around periphery of lesion.
*Hemorrhage.
 
Note:
*The first impression may be that it is [[granuloma|granulomatous inflammation]]; however, the cytoplasm doesn't fit (it isn't bubbly and it isn't sheet-like), and the nuclei aren't quite right (few footprint shaped nuclei).
 
====Images====
<gallery>
Image:Angiomatoid_fibrous_histiocytoma_-_intermed_mag.jpg | AFH - intermed. mag. (WC/Nephron)
Image:Angiomatoid_fibrous_histiocytoma_-_high_mag.jpg | AFH - high mag. (WC/Nephron)
</gallery>
www:
*[http://www.sarcomaimages.com/index.php?v=Angiomatoid-Fibrous-Histiocytoma AFH (sarcomaimages.com)].
*[http://jcp.bmj.com/content/63/2/124/F1.large.jpg AFH (bmj.com)].<ref name=pmid20154033>{{Cite journal  | last1 = Matsumura | first1 = T. | last2 = Yamaguchi | first2 = T. | last3 = Tochigi | first3 = N. | last4 = Wada | first4 = T. | last5 = Yamashita | first5 = T. | last6 = Hasegawa | first6 = T. | title = Angiomatoid fibrous histiocytoma including cases with pleomorphic features analysed by fluorescence in situ hybridisation. | journal = J Clin Pathol | volume = 63 | issue = 2 | pages = 124-8 | month = Feb | year = 2010 | doi = 10.1136/jcp.2009.072256 | PMID = 20154033 | url = http://jcp.bmj.com/content/63/2/124.full }}
</ref>
*[http://path.upmc.edu/cases/case512.html AFH - several images (upmc.edu)].
 
===IHC===
Features:<ref name=Ref_WMSP624-5>{{Ref WMSP|624-5}}</ref>
*CD68 +ve.
*CD57 +ve.
*Desmin +ve.
*Vimentin +ve.
 
===Molecular===
AFH has recurrent [[translocations]]:
*t(12;16) FUS/ATF1.
*t(12;22) EWS/ATF1.


==Aggressive angiomyxoma==
==Aggressive angiomyxoma==
*[[AKA]] deep aggressive angiomyxoma.
*[[AKA]] deep aggressive angiomyxoma.
===General===
{{Main|Aggressive angiomyxoma}}
*Classically a [[vulva]]r mass or (less commonly) a [[scrotum|scrotal]] mass.
**Case report of a thigh lesion.<ref name=pmid18338163>{{Cite journal  | last1 = Heffernan | first1 = EJ. | last2 = Hayes | first2 = MM. | last3 = Alkubaidan | first3 = FO. | last4 = Clarkson | first4 = PW. | last5 = Munk | first5 = PL. | title = Aggressive angiomyxoma of the thigh. | journal = Skeletal Radiol | volume = 37 | issue = 7 | pages = 673-8 | month = Jul | year = 2008 | doi = 10.1007/s00256-008-0465-0 | PMID = 18338163 }}</ref>
*Benign - no metastatic potential.
*"Aggressive" as it has a high recurrance.
 
===Gross===
*Poorly circumscribed.
*"Rubbery" or "gelatinous".
 
Location:
*[[Vulva]] - classic location.
 
Clinical DDx:
*[[Bartholin cyst]].
 
===Microscopic===
Features:<ref name=Ref_WMSP624>{{Ref WMSP|624}}</ref>
#Thick blood vessels that meld into the surrounding stroma - '''key feature'''.
#[[Myxoid stroma]] - '''key feature'''.
#Small stellate cell/spindle cells without significant nuclear atypia.
 
DDx:
*[[Angiomyofibroblastoma]].<ref name=pmid1314521>{{Cite journal  | last1 = Fletcher | first1 = CD. | last2 = Tsang | first2 = WY. | last3 = Fisher | first3 = C. | last4 = Lee | first4 = KC. | last5 = Chan | first5 = JK. | title = Angiomyofibroblastoma of the vulva. A benign neoplasm distinct from aggressive angiomyxoma. | journal = Am J Surg Pathol | volume = 16 | issue = 4 | pages = 373-82 | month = Apr | year = 1992 | doi =  | PMID = 1314521 }}</ref>
*[[Neurofibroma]].
*[[Myxoma]].
 
====Images====
<gallery>
Image:Aggressive_angiomyxoma_-_intermed_mag.jpg | Aggressive angiomyxoma - intermed. mag. (WC/Nephron)
Image:Aggressive_angiomyxoma_-_very_high_mag.jpg | Aggressive angiomyxoma - very high mag. (WC/Nephron)
</gallery>
www:
*[http://www.webpathology.com/image.asp?n=1&Case=99 Aggressive angiomyxoma - low mag. (webpathology.com)].
*[http://www.webpathology.com/image.asp?case=99&n=2 Aggressive angiomyxoma - high mag. (webpathology.com)].
*[http://path.upmc.edu/cases/case538.html Aggressive angiomyxoma - several images (upmc.edu)].
 
===IHC===
Features:<ref name=Ref_WMSP624>{{Ref WMSP|624}}</ref>
*Desmin +ve.
*Vimentin +ve.
*ER +ve.
*PR +ve.


==Angiomyofibroblastoma==
==Angiomyofibroblastoma==
===General===
{{Main|Angiomyofibroblastoma}}
*Uncommon.
 
Clinical DDx:
*[[Bartholin cyst]].
 
===Microscopic===
Features:<ref name=pmid1314521>{{Cite journal  | last1 = Fletcher | first1 = CD. | last2 = Tsang | first2 = WY. | last3 = Fisher | first3 = C. | last4 = Lee | first4 = KC. | last5 = Chan | first5 = JK. | title = Angiomyofibroblastoma of the vulva. A benign neoplasm distinct from aggressive angiomyxoma. | journal = Am J Surg Pathol | volume = 16 | issue = 4 | pages = 373-82 | month = Apr | year = 1992 | doi =  | PMID = 1314521 }}</ref>
*Hypercellular zones and hypocellular edematous zones.
*Small blood vessels (~20 micrometers) - no large blood vessels - '''key feature'''.
*[[Myxoid stroma]] - '''key feature'''.
*Small stellate cell/spindle cells without significant nuclear atypia.
 
DDx:
*[[Aggressive angiomyxoma]] - less cellular, large blood vessels.
 
Images:
*[http://www.webpathology.com/image.asp?case=544&n=4 Angiomyofibroblastoma (webpathology.com)]
*[http://www.webpathology.com/image.asp?n=5&Case=544 Angiomyofibroblastoma - high mag. (webpathology.com)].


==Extrarenal malignant rhabdoid tumour==
==Extrarenal malignant rhabdoid tumour==
*Essentially identical to ''[[renal malignant rhabdoid tumour]]''.<ref name=Ref_WMSP627>{{Ref WMSP|627}}</ref>
*Essentially identical to ''[[renal malignant rhabdoid tumour]]''.<ref name=Ref_WMSP627>{{Ref WMSP|627}}</ref>
===General===
{{Main|Extrarenal malignant rhabdoid tumour}}
*Usu. children < 2 years old.
*Very poor prognosis.
*In the CNS it is known as ''[[atypical teratoid-rhabdoid tumour]]''.<ref name=Ref_WMSP627>{{Ref WMSP|627}}</ref>
 
===Microscopic===
Features:<ref name=Ref_WMSP627>{{Ref WMSP|627}}</ref>
*Variable architecture.
*Round cells.
*Eccentric vesicular nucleus.
*Prominent [[nucleolus]] -- '''key feature'''.
 
===IHC===
*INI1 (SMARCB1) -ve.
**AKA BAF47.


==Ewing sarcoma/PNET==
==Ewing sarcoma/PNET==
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==Epithelioid sarcoma==
==Epithelioid sarcoma==
:Sarcomas with an epithelioid morphology are covered in ''[[epithelioid sarcomas]]''.
:Sarcomas with an epithelioid morphology are covered in ''[[epithelioid sarcomas]]''.
===General===
{{Main|Epithelioid sarcoma}}
*Rare.
*Adolescents, young adults.
*Serum CA-125 may be useful for following clinically.<ref name=pmid19756736>{{Cite journal  | last1 = Hoshino | first1 = M. | last2 = Kawashima | first2 = H. | last3 = Ogose | first3 = A. | last4 = Kudo | first4 = N. | last5 = Ariizumi | first5 = T. | last6 = Hotta | first6 = T. | last7 = Umezu | first7 = H. | last8 = Hatano | first8 = H. | last9 = Morita | first9 = T. | title = Serum CA 125 expression as a tumor marker for diagnosis and monitoring the clinical course of epithelioid sarcoma. | journal = J Cancer Res Clin Oncol | volume = 136 | issue = 3 | pages = 457-64 | month = Mar | year = 2010 | doi = 10.1007/s00432-009-0678-1 | PMID = 19756736 }}</ref>
 
Subclassification:<ref name=pmid9042279>{{cite journal |author=Guillou L, Wadden C, Coindre JM, Krausz T, Fletcher CD |title="Proximal-type" epithelioid sarcoma, a distinctive aggressive neoplasm showing rhabdoid features. Clinicopathologic, immunohistochemical, and ultrastructural study of a series |journal=Am. J. Surg. Pathol. |volume=21 |issue=2 |pages=130–46 |year=1997 |month=February |pmid=9042279 |doi= |url=}}</ref>
*Proximal type:
**More aggressive.
*Distal type:
 
===Microscopic===
Features:<ref>{{Ref WHOSTAB|205}}</ref>
*Epithelioid morphology and spindle morphology - which predominates is dependent on location (see subclassification).
*+/-Prominent nucleolus - '''distinctive feature'''.
*Zonal necrosis with irregular border.
**Descriptors: "Garland necrosis", necrosis with "scalloped border" = necrotic regions with irregular border.
 
Subclassification:<ref name=pmid9042279>{{cite journal |author=Guillou L, Wadden C, Coindre JM, Krausz T, Fletcher CD |title="Proximal-type" epithelioid sarcoma, a distinctive aggressive neoplasm showing rhabdoid features. Clinicopathologic, immunohistochemical, and ultrastructural study of a series |journal=Am. J. Surg. Pathol. |volume=21 |issue=2 |pages=130–46 |year=1997 |month=February |pmid=9042279 |doi= |url=}}</ref>
*Proximal-type (proximal location):
**More epithelioid.
*Distal-type (distal location):
**More spindled.
**Granuloma-like pattern.
 
DDx:
*Carcinoma.
*[[Rheumatoid nodule]].
*[[Granuloma annulare]].
 
====Images====
<gallery>
Image:Epithelioid_sarcoma_-_intermed_mag.jpg | ES - intermed. mag. (WC/Nephron)
Image:Epithelioid_sarcoma_-_high_mag.jpg | ES - high mag. (WC/Nephron)
Image:Epithelioid_sarcoma_-_smarcb1_-_high_mag.jpg | ES - SMARCB1/INI1 - high mag. (WC/Nephron)
</gallery>
www:
*[http://path.upmc.edu/cases/case594.html ES - several images (upmc.edu)].
 
===IHC===
Features:<ref name=pmid10452506>{{cite journal |author=Miettinen M, Fanburg-Smith JC, Virolainen M, Shmookler BM, Fetsch JF |title=Epithelioid sarcoma: an immunohistochemical analysis of 112 classical and variant cases and a discussion of the differential diagnosis |journal=Hum. Pathol. |volume=30 |issue=8 |pages=934–42 |year=1999 |month=August |pmid=10452506 |doi= |url=}}</ref>
*INI1 (SMARCB1<ref>{{OMIM|601607}}</ref>) -ve.<ref name=pmid19997734>{{cite journal |author=Mentzel T |title=[Epithelioid sarcoma: morphologic variants and differential diagnosis] |language=German |journal=Pathologe |volume=31 |issue=2 |pages=135–41 |year=2010 |month=March |pmid=19997734 |doi=10.1007/s00292-009-1250-0 |url=}}</ref>
*Vimentin +ve.
*Various keratins +ve.
**Keratin 8, Keratin 19 +ve.
**34betaE12 +ve/-ve.
*CD34 +ve.
**Malignant rhabdoid tumour -ve.
 
Others:
*S100 -ve (r/o melanoma).
*CK7 +ve / CK20 -ve.<ref name=pmid12680954>{{Cite journal  | last1 = Humble | first1 = SD. | last2 = Prieto | first2 = VG. | last3 = Horenstein | first3 = MG. | title = Cytokeratin 7 and 20 expression in epithelioid sarcoma. | journal = J Cutan Pathol | volume = 30 | issue = 4 | pages = 242-6 | month = Apr | year = 2003 | doi =  | PMID = 12680954 }}</ref>
*CA-125 +ve.<ref name=pmid19756736/><ref name=pmid16740043>{{Cite journal  | last1 = Lee | first1 = HI. | last2 = Kang | first2 = KH. | last3 = Cho | first3 = YM. | last4 = Lee | first4 = OJ. | last5 = Ro | first5 = JY. | title = Proximal-type epithelioid sarcoma with elevated serum CA 125: report of a case with CA 125 immunoreactivity. | journal = Arch Pathol Lab Med | volume = 130 | issue = 6 | pages = 871-4 | month = Jun | year = 2006 | doi = 10.1043/1543-2165(2006)130[871:PESWES]2.0.CO;2 | PMID = 16740043 }}</ref>


==Alveolar soft part sarcoma==
==Alveolar soft part sarcoma==
*Abbreviated ''ASPS''.
{{Main|Alveolar soft part sarcoma}}
===General===
*Adolescents/young adults.
*Children -- classically location: base of [[tongue]] and orbit.
*Typical indolent initially - ultimately a poor prognosis.<ref name=pmid17071801>{{Cite journal  | last1 = Folpe | first1 = AL. | last2 = Deyrup | first2 = AT. | title = Alveolar soft-part sarcoma: a review and update. | journal = J Clin Pathol | volume = 59 | issue = 11 | pages = 1127-32 | month = Nov | year = 2006 | doi = 10.1136/jcp.2005.031120 | PMID = 17071801 |PMC = 1860509 | URL = http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1860509/?tool=pubmed }}</ref>
 
===Microscopic===
Features:<ref name=Ref_WMSP627>{{Ref WMSP|627}}</ref>
*Arranged in nest/separated by thin septa; vaguely resembles alveoli (at low power).
*Large cells (~30-50 μm) with abundant eosinophilic cytoplasm.
*An eccentric nucleus.
*+/-Nucleolus.
 
DDx:
*[[Rhabdomyosarcoma]], alveolar - usu. does not have sheets of rhabdoid cells.
 
====Images====
<gallery>
Image:Alveolar_soft_part_sarcoma_-_low_mag.jpg | ASPS - low mag. (WC/Nephron)
Image:Alveolar_soft_part_sarcoma_-_intermed_mag.jpg | ASPS - intermed. mag. (WC/Nephron)
Image:Alveolar_soft_part_sarcoma_-2-_very_high_mag.jpg | ASPS - very high mag. (WC/Nephron)
</gallery>
www:
*[http://www.webpathology.com/image.asp?case=508&n=10 ASPS - PAS (webpathology.com)].
 
===Stains===
*PAS +ve (cytoplasmic) - considered the most useful.<ref name=pmid17516754>{{Cite journal  | last1 = Zarrin-Khameh | first1 = N. | last2 = Kaye | first2 = KS. | title = Alveolar soft part sarcoma. | journal = Arch Pathol Lab Med | volume = 131 | issue = 3 | pages = 488-91 | month = Mar | year = 2007 | doi = 10.1043/1543-2165(2007)131[488:ASPS]2.0.CO;2 | PMID = 17516754 }}</ref>
*PASD +ve (cytoplasmic).
 
===IHC===
*TFE3 +ve -- suggestive of characteristic translocation.
 
===Molecular===
*t(X;17)(p11.2;q25).<ref>{{OMIM|606243}}</ref>
 
Note:
*Same translocation may be seen in ''[[renal tumour with Xp11.2 translocation]]''.
 
===EM===
*Distinctive membrane-bound intracytoplasmic crystal lattice with ~5 nm fibres spaced 10 nm apart.<ref name=pmid17071801/>
 
Image:
*[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1860509/figure/fig8/ Distinctive crystal lattice in ASPS (nlm.nih.gov)].<ref name=pmid17071801/>


==Desmoplastic small round cell tumour==
==Desmoplastic small round cell tumour==
*Abbreviated ''DSRCT''.
{{Main|Desmoplastic small round cell tumour}}
===General===
*Males > females.
*Usu. affects young adults.
*Typically retroperitoneal.
*Poor prognosis.
 
===Microscopic===
Features:<ref name=pmid10207460>{{cite journal |author=Pickhardt PJ, Fisher AJ, Balfe DM, Dehner LP, Huettner PC |title=Desmoplastic small round cell tumor of the abdomen: radiologic-histopathologic correlation |journal=Radiology |volume=210 |issue=3 |pages=633–8 |year=1999 |month=March |pmid=10207460 |doi= |url=http://radiology.rsna.org/content/210/3/633.full}}</ref>
#Broad bands of paucicellular fibrous stroma with:
#Small round cells in nests with an undulating sharp border.
#*The small round cells lack distinct nucleoli and have scant cytoplasm; they are ''[[small round cell tumour]]'' cells.
 
Notes:
*Usu. abundant mitoses.
*+/-Necrosis.
 
DDx:
*Metastatic [[germ cell tumour]] (DDx of location and age).
*[[Embryonal RMS]].
**It should be noted that DSRCT, like embryonal RMS, is +ve for desmin!
*Solid variant of [[alveolar RMS]].
**Nests in alveolar RMS have round edges.
 
====Images====
<gallery>
Image:Desmoplastic_small_round_cell_tumour_-_intermed_mag.jpg | DSRCT - intermed. mag. (WC/Nephron)
Image:Desmoplastic_small_round_cell_tumour_-_very_high_mag.jpg | DSRCT - very high mag. (WC/Nephron)
</gallery>
 
===IHC===
Features:
*AE1/AE3 +ve.
*Desmin +ve.
*EMA +ve.
*Actin -ve.
*WT1 (N-terminal) -ve.
*WT1 (C-terminal) +ve.
*CD57 +ve.
 
===Molecular===
*t(11;22)(p13;q12).<ref name=pmid17964965>{{cite journal |author=Lee YS, Hsiao CH |title=Desmoplastic small round cell tumor: a clinicopathologic, immunohistochemical and molecular study of four patients |journal=J. Formos. Med. Assoc. |volume=106 |issue=10 |pages=854–60 |year=2007 |month=October |pmid=17964965 |doi=10.1016/S0929-6646(08)60051-0 |url=}}</ref><ref>{{cite journal |author=Lal DR, Su WT, Wolden SL, Loh KC, Modak S, La Quaglia MP |title=Results of multimodal treatment for desmoplastic small round cell tumors |journal=J. Pediatr. Surg. |volume=40 |issue=1 |pages=251–5 |year=2005 |month=January |pmid=15868593 |doi=10.1016/j.jpedsurg.2004.09.046 |url=http://www.dsrct.com/JPS%20Article.pdf}}</ref>


==Clear cell sarcoma==
==Clear cell sarcoma==
*Known among pathologists as "soft-tissue melanoma" and "melanoma of the soft parts", as it has a strong morphological resemblance.<ref name=pmid18300804>{{cite journal |author=Hisaoka M, Ishida T, Kuo TT, ''et al.'' |title=Clear cell sarcoma of soft tissue: a clinicopathologic, immunohistochemical, and molecular analysis of 33 cases |journal=Am. J. Surg. Pathol. |volume=32 |issue=3 |pages=452–60 |year=2008 |month=March |pmid=18300804 |doi=10.1097/PAS.0b013e31814b18fb |url=}}</ref>
{{Main|Clear cell sarcoma}}
*Not to be confused with ''[[clear cell sarcoma of the kidney]]''.
 
===General===
*Molecular changes and origin distinct from [[malignant melanoma]].
*Incidence: rare soft tissue tumour.
 
====Clinical====
*Usually - deep soft tissue ''or'' extremities.
**Classically associated with tendons and aponeuroses.<ref name=pmid17227118>{{Cite journal  | last1 = Dim | first1 = DC. | last2 = Cooley | first2 = LD. | last3 = Miranda | first3 = RN. | title = Clear cell sarcoma of tendons and aponeuroses: a review. | journal = Arch Pathol Lab Med | volume = 131 | issue = 1 | pages = 152-6 | month = Jan | year = 2007 | doi = 10.1043/1543-2165(2007)131[152:CCSOTA]2.0.CO;2 | PMID = 17227118 }}</ref>
*Guarded prognosis.
*First described in 1965.<ref>URL: [http://www.informaworld.com/smpp/723576818-750600/ftinterface~db=all~content=a789166263~fulltext=713240928 http://www.informaworld.com/smpp/723576818-750600/ftinterface~db=all~content=a789166263~fulltext=713240928]. Accessed on: 5 May 2010.</ref>
 
===Microscopic===
Features:<ref name=pmid18300804/>
*Architecture: sheeting ''or'' fascicular (bundles) arrangement.
**Fibrous septae - between tumour cells.
*Tumour cells uniform (low pleomorphism) - spindle-shaped ''or'' epithelioid:
**Classically have clear cytoplasm.
**Prominent nucleoli - basophilic - '''key feature'''.
**+/-Binucleation.
 
DDx:
*[[Malignant melanoma]].
*[[PEComa]].
*Carcinoma.
 
====Images====
<gallery>
Image:Clear_cell_sarcoma_-_intermed_mag.jpg | Clear cell sarcoma - intermed. mag. (WC)
Image:Clear_cell_sarcoma_-_very_high_mag.jpg | Clear cell sarcoma - very high mag. (WC)
Image:Clear_cell_sarcoma.Image12.jpg | Clear cell sarcoma (WC/Gardner)
</gallery>
===IHC===
Features:<ref name=pmid18300804/>
*S100 +ve.
*HMB-45 +ve.
*Melan A (MART-1) +ve; sometimes -ve.
*BCL2 +ve.
*CD57 +ve (usually).
 
Keratins:
*EMA may be +ve.
*CAM5.2 -ve.
*AE1/AE3 -ve.
 
===Molecular studies===
*[[Chromosomal translocation]] t(12;22)(q13;q12).<ref name=pmid18300804/>
**Fusion transcripts:
***EWSR1-ATF1.
****Same translocation in: ''[[myxoid liposarcoma]]'',<ref name=pmid21115923>{{Cite journal  | last1 = Suzuki | first1 = K. | last2 = Matsui | first2 = Y. | last3 = Endo | first3 = K. | last4 = Kubo | first4 = T. | last5 = Hasegawa | first5 = T. | last6 = Kimura | first6 = T. | last7 = Ohtani | first7 = O. | last8 = Yasui | first8 = N. | title = Myxoid liposarcoma with EWS-CHOP type 1 fusion gene. | journal = Anticancer Res | volume = 30 | issue = 11 | pages = 4679-83 | month = Nov | year = 2010 | doi =  | PMID = 21115923 }}</ref> and ''[[hyalinizing clear cell carcinoma]]''.
***EWSR1-CREB1 (GI tract associated).


==Synovial sarcoma==
==Synovial sarcoma==
*Abbreviated ''SS''.
{{Main|Synovial sarcoma}}
 
===General===
*Does not arise from cartilage.<ref name=Ref_WMSP627>{{Ref WMSP|627}}</ref>
*Young adults or adolescents.
**Classic age: 30s.
*Poor prognosis.
 
Clinical:<ref name=pmid16973781>{{Cite journal  | last1 = Murphey | first1 = MD. | last2 = Gibson | first2 = MS. | last3 = Jennings | first3 = BT. | last4 = Crespo-Rodríguez | first4 = AM. | last5 = Fanburg-Smith | first5 = J. | last6 = Gajewski | first6 = DA. | title = From the archives of the AFIP: Imaging of synovial sarcoma with radiologic-pathologic correlation. | journal = Radiographics | volume = 26 | issue = 5 | pages = 1543-65 | month =  | year =  | doi = 10.1148/rg.265065084 | PMID = 16973781 | URL = http://radiographics.rsna.org/content/26/5/1543.long }}</ref>
*Present with soft palpable mass - slow growing - often for years.
*May present with pain.
**Uncommon finding in sarcomas.
 
===Gross===
Location:
*Usually close to a joint.
*Usually distal extremity ~65% of cases.<ref name=pmid16973781/>
**Upper extremity ~20% of cases.<ref name=pmid16973781/>
 
Appearance - often non-specific:
*Solid often lobulated +/- cystic component.
*Grey-yellow.
*Pushing border to ill-defined border.
 
Images:
*[http://www.sarcomaimages.com/images/db/synovial-sarcoma/synovial-sarcoma-01-gross-image,-sarcoma-images.jpg SS (sarcomaimages.com)].<ref>URL: [http://www.sarcomaimages.com/index.php?v=Synovial-Sarcoma http://www.sarcomaimages.com/index.php?v=Synovial-Sarcoma]. Accessed on: 2 April 2012.</ref>
*[http://www.tumorlibrary.com/case/detail.jsp?image_id=2462 SS (tumorlibrary.com)].
 
===Microscopic===
Comes in three (histologic) flavours:<ref name=Ref_WMSP627>{{Ref WMSP|627}}</ref><ref>{{cite journal |author=Schaal CH, Navarro FC, Moraes Neto FA |title=Primary renal sarcoma with morphologic and immunohistochemical aspects compatible with synovial sarcoma |journal=Int Braz J Urol |volume=30 |issue=3 |pages=210–3 |year=2004 |pmid=15689250 |doi= |url=http://www.brazjurol.com.br/may_june_2004/Schaal_ing_210_213.htm}}</ref>
#Spindle cell sarcoma with features of hemangiopericytoma, i.e. [[staghorn vessels]].
#Biphasic synovial sarcoma:
##Spindle cells with features of hemangiopericytoma.
##Epitheliod glands or nests.
#Primitive round cell type.
 
Features:
*[[Herring bone]] or [[vesicular pattern]] - '''key feature'''.
*Spindle cells.
*+/-Glandular component - typically more pink.
*+/-Calcification - uncommon.
**Extensive calcification = better prognosis.<ref name=pmid6282441>{{Cite journal  | last1 = Varela-Duran | first1 = J. | last2 = Enzinger | first2 = FM. | title = Calcifying synovial sarcoma. | journal = Cancer | volume = 50 | issue = 2 | pages = 345-52 | month = Jul | year = 1982 | doi =  | PMID = 6282441 }}</ref>
 
DDx:
*[[MPNST]].
**Can be difficult.
 
====Images====
<gallery>
Image:Monophasic_synovial_sarcoma_-_intermed_mag.jpg | Monophasic synovial sarcoma with staghorn vessels - intermed. mag. (WC/Nephron)
</gallery>
www:
*[http://www.scielo.br/img/revistas/ibju/v30n3/3a06f03.jpg Synovial sarcoma (scielo.br)].
*[http://www.humpath.com/spip.php?page=article&id_article=1965 Synovial sarcoma - collection of images (humpath.com)].
*[http://path.upmc.edu/cases/case292.html Synovial sarcoma - several images (upmc.edu)].
*[http://radiographics.rsna.org/content/26/5/1543/F14.expansion.html Biphasic SS (radiographics.rsna.org)].
*[http://radiographics.rsna.org/content/26/5/1543.long Monophasic SS (radiographics.rsna.org)].
 
===IHC===
Features:<ref name=Ref_WMSP627>{{Ref WMSP|627}}</ref>
*Vimentin +ve.
*EMA +ve.
*BCL2 +ve.
*CD99 +ve.
 
Others:
*Beta-catenin +ve ~30-70%.<ref name=pmid16740029>{{cite journal |author=Horvai AE, Kramer MJ, O'Donnell R |title=Beta-catenin nuclear expression correlates with cyclin D1 expression in primary and metastatic synovial sarcoma: a tissue microarray study |journal=Arch. Pathol. Lab. Med. |volume=130 |issue=6 |pages=792–8 |year=2006 |month=June |pmid=16740029 |doi= |url=}}</ref>
*Cyclin D1 ~50%.<ref name=pmid16740029/><ref name=pmid15375433>{{cite journal |author=Ng TL, Gown AM, Barry TS, ''et al.'' |title=Nuclear beta-catenin in mesenchymal tumors |journal=Mod. Pathol. |volume=18 |issue=1 |pages=68–74 |year=2005 |month=January |pmid=15375433 |doi=10.1038/modpathol.3800272 |url=}}</ref>
*TLE1 +ve nuclear staining; not specific for synovial sarcoma.<ref name=pmid19363472>{{cite journal |author=Kosemehmetoglu K, Vrana JA, Folpe AL |title=TLE1 expression is not specific for synovial sarcoma: a whole section study of 163 soft tissue and bone neoplasms |journal=Mod. Pathol. |volume=22 |issue=7 |pages=872–8 |year=2009 |month=July |pmid=19363472 |doi=10.1038/modpathol.2009.47 |url=http://www.nature.com/modpathol/journal/v22/n7/full/modpathol200947a.html}}</ref><ref>{{cite journal |author=Seo SW, Lee H, Lee HI, Kim HS |title=The role of TLE1 in synovial sarcoma |journal=J Orthop Res |volume= |issue= |pages= |year=2011 |month=February |pmid=21319215 |doi=10.1002/jor.21318 |url=}}</ref>
 
Typically negative:<ref>URL: [http://path.upmc.edu/cases/case292/dx.html http://path.upmc.edu/cases/case292/dx.html]. Accessed on: 14 January 2012.</ref>
*CD34.
*S100 ~30% +ve.
*SMA.
 
Notes:
*Synovial sarcoma & MPNST:
**Both +ve: PGP9.5 (UCHL1<ref>{{OMIM|191342}}</ref>), S100, NGFR, CD56, CD99, vimentin.
**Synovial +ve: EMA, keratin, BCL2, TLE1.
**MPNST +ve: nestin, CD34.
 
Trivia:
*PGP in ''PGP9.5'' = protein gene product.<ref name=pmid6343558>{{Cite journal  | last1 = Doran | first1 = JF. | last2 = Jackson | first2 = P. | last3 = Kynoch | first3 = PA. | last4 = Thompson | first4 = RJ. | title = Isolation of PGP 9.5, a new human neurone-specific protein detected by high-resolution two-dimensional electrophoresis. | journal = J Neurochem | volume = 40 | issue = 6 | pages = 1542-7 | month = Jun | year = 1983 | doi =  | PMID = 6343558 }}</ref>
 
===EM===
Features:<ref name=pmid9930576>{{Cite journal  | last1 = Fisher | first1 = C. | title = Synovial sarcoma. | journal = Ann Diagn Pathol | volume = 2 | issue = 6 | pages = 401-21 | month = Dec | year = 1998 | doi =  | PMID = 9930576 }}</ref>
*Biphasic tumour have biphasic ultrastructural features (unlike spindle cell carcinoma and [[epithelioid sarcoma]]).
*Epithelioid component is adenocarcinoma-like - they have:
**Intermediate filaments.
**[[Tonofilament]]s.
**Microvilli.
*[[Spindle cell]] component - mostly features less.
**Poorly formed desmosomes.
**No intermediate filaments, no myofilaments.
 
===Molecular pathology===
Associated [[translocation]]:
*t(X;18)(p11.2;q11.2).<ref>URL: [http://www.ncbi.nlm.nih.gov/omim/300813 http://www.ncbi.nlm.nih.gov/omim/300813]. Accessed on: 30 May 2010.</ref>
**SYT/SSX fusion gene.
 
Several SSX genes - cannot be differentiated with standard karyotyping:
*SSX1.
*SSX2 - better survival, rarely seen in biphasic tumours.<ref>{{Ref APBR|625 Q6}}</ref>
*SSX4 - uncommon.
 
Notes:
*At HSC t(X,18) = synovial sarcoma.


=Other=
=Other=
==Granulocytic sarcoma==
==Granulocytic sarcoma==
*Common alternate terms: myeloid sarcoma, chloroma.
*Common alternate terms: extramedullary leukemia,<ref name=pmid21795742>{{Cite journal  | last1 = Bakst | first1 = RL. | last2 = Tallman | first2 = MS. | last3 = Douer | first3 = D. | last4 = Yahalom | first4 = J. | title = How I treat extramedullary acute myeloid leukemia. | journal = Blood | volume = 118 | issue = 14 | pages = 3785-93 | month = Oct | year = 2011 | doi = 10.1182/blood-2011-04-347229 | PMID = 21795742 }}</ref> myeloid sarcoma, chloroma.  
*Other terms:<ref name=pmid21556238>{{Cite journal  | last1 = Eom | first1 = KS. | last2 = Kim | first2 = TY. | title = Intraparenchymal myeloid sarcoma and subsequent spinal myeloid sarcoma for acute myeloblastic leukemia. | journal = J Korean Neurosurg Soc | volume = 49 | issue = 3 | pages = 171-4 | month = Mar | year = 2011 | doi = 10.3340/jkns.2011.49.3.171 | PMID = 21556238 | PMC = 3085814 | url = http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3085814/ }}</ref> myeloblastoma, chloromyeloma, chloromyelosarcoma, granulocytic leukosarcoma, or myelosarcoma.
*Other terms:<ref name=pmid21556238>{{Cite journal  | last1 = Eom | first1 = KS. | last2 = Kim | first2 = TY. | title = Intraparenchymal myeloid sarcoma and subsequent spinal myeloid sarcoma for acute myeloblastic leukemia. | journal = J Korean Neurosurg Soc | volume = 49 | issue = 3 | pages = 171-4 | month = Mar | year = 2011 | doi = 10.3340/jkns.2011.49.3.171 | PMID = 21556238 | PMC = 3085814 | url = http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3085814/ }}</ref> myeloblastoma, chloromyeloma, chloromyelosarcoma, granulocytic leukosarcoma, or myelosarcoma.
 
{{Main|Granulocytic sarcoma}}
===General===
*Soft tissue manifestation of acute myeloid leukemia.<ref name=pmid21556238/>
 
===Microscopic===
Features:
*Cluster of atypical small blue cells in [[soft tissue lesions|soft tissue]].
 
Note:
*May mimic [[small cell carcinoma]], large cell lymphomas ([[DLBCL]], [[ALCL]]), [[small round cell tumour]]s.
 
====Images====
<gallery>
Image:Chloroma_-_high_mag.jpg | Chloroma - high mag. (WC)
Image:Chloroma_-_very_high_mag.jpg | Chloroma - very high mag. (WC)
</gallery>
www:
*[http://path.upmc.edu/cases/case306/micro.html Granulocytic sarcoma - several crappy images (upmc.edu)].
*[http://path.upmc.edu/cases/case379.html Myeloid sarcoma - several images (upmc.edu)].


=See also=
=See also=

Latest revision as of 12:50, 3 November 2015

Soft tissue lesions strike fear in many pathologists as they are uncommon and may be difficult to diagnose. Malignant soft tissue lesions, i.e. cancerous soft tissue lesions, are usually sarcomas. Sarcomas are malignancies derived from mesenchymal tissue.

Introduction

WHO classification of soft tissue lesions/tumours

Morphologic grouping

These include:[1]

  1. Adipocytic tumours.
  2. Fibroblastic/myofibroblastic tumours.
  3. "Fibrohistiocytic" tumours.
  4. Smooth muscle tumours.
  5. Skeletal muscle tumours.
  6. Vascular tumours.
  7. Perivascular (pericytic) tumours.
  8. Chondro-osseous tumours.
  9. Tumours of uncertain differentiation.

Biologic potential grouping

These include:[2]

  1. Benign.
  2. Intermediate (locally aggressive).
  3. Intermediate (rarely metastasizing).
  4. Malignant.

Prevalence

  • All sarcomas are rare buggers.
    • As the classification has been changing over the past years (with more subtypes being recognized/identified) numbers are variable from study-to-study.
  • Once upon a time almost everything was called malignant fibrous histiocytoma; thus, it is listed as a common entity in some publications.

Most common:[3]

  • Liposarcoma.
  • Leiomyosarcoma.

Molecular testing

  • Molecular testing plays an important role in soft tissue pathology.
  • It is generally seen as an adjunct test that:[4]
    • Often is used to confirm the histomorphologic impression/quality control.
    • Frequently has some prognostic significance.
    • May directly affect treatment.

Translocations

Morphohistologic patterns

Name Description DDx Image(s)
Storiform, AKA patternless pattern[5] whorled, cartwheel-like arrangement pleomorphic undifferentiated sarcoma, solitary fibrous tumour, dermatofibrosarcoma protuberans, dermatofibroma[6]
Patternless pattern. (WC)
Herring bone like herring bone (technique) for climbing a hill in cross country skiing; books on a shelf, where they have partially fallen over -- on the one shelf to the left and the one below to the right fibrosarcoma, synovial sarcoma, MPNST
Herring bone. (WC)
Fascicular the long axis of the (spindle) cells are perpendicular to one another in adjacent bundles of cells leiomyoma, leiomyosarcoma
Fascicular pattern. (WC)
Biphasic nests of cells and stroma synovial sarcoma, DSRCT, alveolar RMS
DSRCT. (WC)

Notes:

  • Memory device: herring bone DDx MSF = MPNST, Synovial sarcoma, Fibrosarcoma.

Grading

  • Several systems exist.
  • The US-CAP advocates the use of the French system over the NCI system.
    • The French system is a better predictor metastases and mortality.[7]

French system

  • Formally known as the grading system from the French Federation of Cancer Centres Sarcoma Group (FNCLCC).

Overview

Components - overview:[7][8]

  1. Differentiation (score 1-3).
    • De facto, this is mostly the histologic type.
  2. Mitotic rate (score 1-3).
  3. Necrosis (score 0-2)

Obtaining a score:

  • Add all the points from the three components.

Scoring:

  • Grade 1 = 2-3.
  • Grade 2 = 4-5.
  • Grade 3 = 6-8.
Differentiation
  • Standardized for histologic types.
  • Most tumours = 3/3.

Exceptions:[8]

A group of tumours is not graded:[8]

Mitotic rate
  • 0-9 mitoses/10 HPF.
  • 10-19 mitoses/10 HPF.
  • >=20 mitoses/10 HPF.

Notes:

  • 1 HPF = 0.1734 mm^2.
    • Most resident microscopes have a field of view = 0.2376 mm^2.
      • Thus, ~7.3 HPFs on a resident microscope corresponds to 10 US-CAP HPFs.
Necrosis
  • None = score 0.
  • <=50% of tumour = score 1.
  • >50% of tumour = score 2.

System used by some at MSH

Some pathologists at MSH use the system advocated by Costa et al..[9]

Scoring

  • Grade 1 = 1 point.
  • Grade 2 = 2 points.
  • Grade 3 = 3-4 points.

Components

Points for each of the following:

  • Mitotic activity >= 6 / 10 HPF @ 40X - definition suffers from HPFitis.
  • Pleomorphism present.
  • Cellularity (cells/matrix) > 50%.
  • Necrosis >15% - microscopic (without targeting necrosis grossly) or grossly.

Stage

Lymph node metastases in sarcomas

Sarcomas more likely to be found in the lymph nodes - mnemonic RACE For MS:[12]

DDx by history/site

Retroperiteum

  1. Liposarcoma.
  2. Undifferentiated pleomorphic sarcoma.
  3. Leiomyosarcoma.
  4. MPNST.

Note: Synovial sarcoma and fibrosarcoma are very rare in the retroperitoneum.

Young person - extremity sarcoma

  1. Epithelioid sarcoma.
  2. Synovial sarcoma.

Gross characteristics

  • Usually non-specific.
  • Most sarcomas have a pushing border.
    • If there is an infiltrative border think: (1) fibromatosis, (2) carcinoma.

Adipocytic tumours

This category includes:

  • Lipoma.
  • Liposarcoma.
  • Hibernoma.

Smooth muscle tumours

IHC markers: desmin, SMA, H-caldemsin (most specific).

Leiomyosarcoma

Microscopic

Features (summary):

  • Fasicular cellular spindle cell lesion with:
    • Nuclear atypia.
    • Necrosis.
    • High mitotic rate.

Fibrohistiocytic tumours

Fibrohistiocytic refers (only) to the histomorphologic appearance and therefore may be written in quotation marks; these tumours are not derived from histiocytes (or tissue macrophages), as the name implies.[13]

Pleomorphic undifferentiated sarcoma

  • Abbreviated PUS.
  • AKA Undifferentiated pleomorphic sarcoma, abbreviated UPS.
  • Previously known as malignant fibrous histiocytoma, abbreviated MFH.[14]

Fibroblastic/myofibroblastic tumours

This is a very large and important group of soft tissue lesions. It is covered in a separate article.

The grouping includes:

Perivascular tumours

This grouping includes only two:[15]

Vascular lesions

Vascular lesions are "too red"; they have too many RBCs.

They include:

Skeletal muscle tumours

Rhabdomyoma

Rhabdomyosarcoma

  • Abbreviated RMS.

Comes it two main flavours:

  • Alveolar rhabdomyosarcoma.
  • Embryonal rhabdomyosarcoma.

The histology may be that of a small round cell tumour.

Chondro-osseous tumours

This grouping includes tumours derived from cartilage and bone.

Tumours of uncertain differentiation

Angiomatoid fibrous histiocytoma

Aggressive angiomyxoma

  • AKA deep aggressive angiomyxoma.

Angiomyofibroblastoma

Extrarenal malignant rhabdoid tumour

Ewing sarcoma/PNET

Epithelioid sarcoma

Sarcomas with an epithelioid morphology are covered in epithelioid sarcomas.

Alveolar soft part sarcoma

Desmoplastic small round cell tumour

Clear cell sarcoma

Synovial sarcoma

Other

Granulocytic sarcoma

  • Common alternate terms: extramedullary leukemia,[17] myeloid sarcoma, chloroma.
  • Other terms:[18] myeloblastoma, chloromyeloma, chloromyelosarcoma, granulocytic leukosarcoma, or myelosarcoma.

See also

References

  1. Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 601-3. ISBN 978-0781765275.
  2. Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 598-604. ISBN 978-0781765275.
  3. Skubitz KM, D'Adamo DR (November 2007). "Sarcoma". Mayo Clin. Proc. 82 (11): 1409–32. PMID 17976362. http://www.mayoclinicproceedings.com/content/82/11/1409.long.
  4. Fletcher CD, Fletcher JA, Dal Cin P, Ladanyi M, Woodruff JM (July 2001). "Diagnostic gold standard for soft tissue tumours: morphology or molecular genetics?". Histopathology 39 (1): 100–3. PMID 11454050.
  5. Mangano WE, Cagle PT, Churg A, Vollmer RT, Roggli VL (August 1998). "The diagnosis of desmoplastic malignant mesothelioma and its distinction from fibrous pleurisy: a histologic and immunohistochemical analysis of 31 cases including p53 immunostaining". Am. J. Clin. Pathol. 110 (2): 191–9. PMID 9704618.
  6. Meister P, Höhne N, Konrad E, Eder M (July 1979). "Fibrous histiocytoma: an analysis of the storiform pattern". Virchows Arch A Pathol Anat Histol 383 (1): 31–41. PMID 224569.
  7. 7.0 7.1 Guillou L, Coindre JM, Bonichon F, et al. (January 1997). "Comparative study of the National Cancer Institute and French Federation of Cancer Centers Sarcoma Group grading systems in a population of 410 adult patients with soft tissue sarcoma". J. Clin. Oncol. 15 (1): 350–62. PMID 8996162.
  8. 8.0 8.1 8.2 URL: http://www.cap.org/apps/docs/committees/cancer/cancer_protocols/2011/SoftTissue_11protocol.pdf. Accessed on: 12 April 2011.
  9. Costa J, Wesley RA, Glatstein E, Rosenberg SA (February 1984). "The grading of soft tissue sarcomas. Results of a clinicohistopathologic correlation in a series of 163 cases". Cancer 53 (3): 530–41. PMID 6692258.
  10. 10.0 10.1 Fong, Y.; Coit, DG.; Woodruff, JM.; Brennan, MF. (Jan 1993). "Lymph node metastasis from soft tissue sarcoma in adults. Analysis of data from a prospective database of 1772 sarcoma patients.". Ann Surg 217 (1): 72-7. PMC 1242736. PMID 8424704. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1242736/.
  11. URL: http://www.cap.org/apps/docs/committees/cancer/cancer_protocols/2011/SoftTissue_11protocol.pdf. Accessed on: 28 March 2012.
  12. URL: http://www.aippg.net/forum/f21/surgery-mnemonics-79897/. Accessed on: 23 March 2012.
  13. Luzar, B.; Calonje, E. (Jan 2010). "Cutaneous fibrohistiocytic tumours - an update.". Histopathology 56 (1): 148-65. doi:10.1111/j.1365-2559.2009.03447.x. PMID 20055912.
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