Difference between revisions of "Soft tissue lesions"

From Libre Pathology
Jump to navigation Jump to search
 
(125 intermediate revisions by 2 users not shown)
Line 1: Line 1:
'''Soft tissue lesions''' strike fear in many pathologists as they are uncommon and may be difficult to diagnose.  
'''Soft tissue lesions''' strike fear in many pathologists as they are uncommon and may be difficult to diagnose. Malignant soft tissue lesions, i.e. [[cancer|cancerous]] soft tissue lesions, are usually '''sarcomas'''. Sarcomas are malignancies derived from mesenchymal tissue. 


=Introduction=
=Introduction=
==WHO classification of soft tissue lesions/tumours==
==WHO classification of soft tissue lesions/tumours==
===Morphologic grouping<ref name=Ref_WMSP601-3>{{Ref WMSP|601-3}}</ref>===
===Morphologic grouping===
#Adipocytic tumours.
These include:<ref name=Ref_WMSP601-3>{{Ref WMSP|601-3}}</ref>
#Fibroblastic/myofibroblastic tumours.
#[[Adipocytic tumours]].
#"Fibrohistiocytic" tumours.
#[[Fibroblastic/myofibroblastic tumours]].
#Smooth muscle tumours.
#[[Fibrohistiocytic tumours|"Fibrohistiocytic" tumours]].
#Skeletal muscle tumours.
#[[Smooth muscle tumours|Smooth muscle tumours]].
#Vascular tumours.
#[[Soft tissue lesions#Skeletal muscle tumours|Skeletal muscle tumours]].
#Perivascular (pericytic) tumours.
#[[Vascular tumours]].
#Chondro-osseous tumours.
#[[Soft_tissue_lesions#Perivascular_tumours|Perivascular (pericytic) tumours]].
#Tumours of uncertain differentiation.
#[[Chondro-osseous tumours]].
#[[Soft tissue lesions#Tumours of uncertain differentiation|Tumours of uncertain differentiation]].


===Biologic potential grouping<ref>{{Ref WMSP|598-604}}</ref>===
===Biologic potential grouping===
These include:<ref>{{Ref WMSP|598-604}}</ref>
#Benign.
#Benign.
#Intermediate (locally aggressive).
#Intermediate (locally aggressive).
Line 25: Line 27:
*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 41: Line 43:
*Many tumours in soft tissue pathology are diagnosed inconjunction with the finding of [[chromosomal translocations]].
*Many tumours in soft tissue pathology are diagnosed inconjunction with the finding of [[chromosomal translocations]].


==Histologic patterns==
==Morphohistologic 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
Line 47: Line 50:
! 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>
| whorled, cartwheel-like arrangement
| whorled, cartwheel-like arrangement
| [[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>
| [http://commons.wikimedia.org/w/index.php?title=File:Storiform_pattern_-_intermed_mag.jpg intermed. mag.], [http://commons.wikimedia.org/wiki/File:Storiform_pattern_-_very_high_mag.jpg very high mag.]
| [[Image:Storiform_pattern_-_intermed_mag.jpg |thumb|center|150px| Patternless pattern. (WC)]]
| other ?
|-
|-
| Herring bone
| 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
| 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]]
| [[fibrosarcoma]], [[synovial sarcoma]], [[MPNST]]
| [http://commons.wikimedia.org/wiki/File:Malignant_peripheral_nerve_sheath_tumour_-_intermed_mag.jpg intermed. mag.], [http://commons.wikimedia.org/wiki/File:Malignant_peripheral_nerve_sheath_tumour_-_high_mag.jpg high mag.]  
| [[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 ?
| [[Image:Cutaneous_leiomyosarcoma_-_high_mag.jpg |thumb|center|150px| Fascicular pattern. (WC)]]
| other ?
|-
|-
| Biphasic
| Biphasic
| nests of cells and stroma
| nests of cells and stroma
| [[synovial sarcoma]], [[DSRCT]], [[alveolar RMS]]
| [[synovial sarcoma]], [[DSRCT]], [[alveolar RMS]]
| image ?
| [[Image:Desmoplastic_small_round_cell_tumour_-_high_mag.jpg|thumb|center|150px| DSRCT. (WC)]]
| other ?
|- <!--
|- <!--
| name ?
| name ?
| description ?
| description ?
| DDx ?
| DDx ?
| image ?
| image ? -->
| other ? -->
|}
|}


Line 89: Line 86:


===French system===
===French system===
Overview:<ref name=pmid8996162/><ref name=uscap_stp>URL: [http://www.cap.org/apps/docs/committees/cancer/cancer_protocols/2011/SoftTissue_11protocol.pdf http://www.cap.org/apps/docs/committees/cancer/cancer_protocols/2011/SoftTissue_11protocol.pdf]. Accessed on: 12 April 2011.</ref>
*Formally known as the grading system from the ''French Federation of Cancer Centres Sarcoma Group'' (FNCLCC).
 
====Overview====
Components - overview:<ref name=pmid8996162/><ref name=uscap_stp>URL: [http://www.cap.org/apps/docs/committees/cancer/cancer_protocols/2011/SoftTissue_11protocol.pdf http://www.cap.org/apps/docs/committees/cancer/cancer_protocols/2011/SoftTissue_11protocol.pdf]. Accessed on: 12 April 2011.</ref>
#Differentiation (score 1-3).
#Differentiation (score 1-3).
#*De facto, this is mostly the ''histologic type''.
#*De facto, this is mostly the ''histologic type''.
Line 110: Line 110:
*Well-differentiated liposarcoma = 1.
*Well-differentiated liposarcoma = 1.
*Myxoid liposarcoma = 2.
*Myxoid liposarcoma = 2.
*Conventional liposarcoma = 2.
*Conventional [[liposarcoma]] = 2.
*Fibrosarcoma = 2.
*Fibrosarcoma = 2.
*Myxofibrosarcoma =2.
*[[Myxofibrosarcoma]] =2.


A group of tumours is not graded:<ref name=uscap_stp/>
A group of tumours is not graded:<ref name=uscap_stp/>
Line 119: Line 119:
*[[Alveolar soft part sarcoma]].
*[[Alveolar soft part sarcoma]].
*[[Clear cell sarcoma]].
*[[Clear cell sarcoma]].
*Extraskeletal myxoid chondrosarcoma.
*[[Extraskeletal myxoid chondrosarcoma]].


=====Mitotic rate=====
=====Mitotic rate=====
Line 150: Line 150:
*Cellularity (cells/matrix) > 50%.
*Cellularity (cells/matrix) > 50%.
*Necrosis >15% - microscopic (without targeting necrosis grossly) ''or'' grossly.
*Necrosis >15% - microscopic (without targeting necrosis grossly) ''or'' grossly.
==Stage==
{{Main|Cancer staging systems}}
===Lymph node metastases in sarcomas===
{{Main|Lymph node metastasis}}
*[[Lymph node]] (LN) spread is uncommon in sarcomas; [[lymph node metastases]] are seen in <3% of cases.<ref name=pmid8424704>{{Cite journal  | last1 = Fong | first1 = Y. | last2 = Coit | first2 = DG. | last3 = Woodruff | first3 = JM. | last4 = Brennan | first4 = MF. | title = Lymph node metastasis from soft tissue sarcoma in adults. Analysis of data from a prospective database of 1772 sarcoma patients. | journal = Ann Surg | volume = 217 | issue = 1 | pages = 72-7 | month = Jan | year = 1993 | doi =  | PMID = 8424704 | PMC = 1242736}}</ref>
**Many sarcomas are reported in LNs.
***According to the [[CAP checklist]] for soft tissue<ref>URL: [http://www.cap.org/apps/docs/committees/cancer/cancer_protocols/2011/SoftTissue_11protocol.pdf http://www.cap.org/apps/docs/committees/cancer/cancer_protocols/2011/SoftTissue_11protocol.pdf]. Accessed on: 28 March 2012.</ref> the most common are: [[epithelioid sarcoma]] and [[clear cell sarcoma]].
***According to Fong ''et al.''<ref name=pmid8424704/> the most commonly is: angiosarcoma.
Sarcomas more likely to be found in the lymph nodes - mnemonic ''RACE For MS'':<ref>URL: [http://www.aippg.net/forum/f21/surgery-mnemonics-79897/ http://www.aippg.net/forum/f21/surgery-mnemonics-79897/]. Accessed on: 23 March 2012.</ref>
*[[rhabdomyosarcoma|'''R'''habdomyosarcoma]]
*[[Angiosarcoma|'''A'''ngiosarcoma]].
*[[clear cell sarcoma|'''C'''lear cell sarcoma]].
*[[epithelioid sarcoma|'''E'''pitheliod sarcoma]].
*[[fibrosarcoma|'''F'''ibrosarcoma]].
*[[pleomorphic undifferentiated sarcoma|'''M'''alignant fibrous histiocytoma (pleomorphic undifferentiated sarcoma)]].
*[[synovial sarcoma|'''S'''ynovial cell sarcoma]].
==DDx by history/site==
===Retroperiteum===
#[[Liposarcoma]].
#[[Undifferentiated pleomorphic sarcoma]].
#[[Leiomyosarcoma]].
#[[MPNST]].
Note:
[[Synovial sarcoma]] and [[fibrosarcoma]] are very rare in the retroperitoneum.
===Young person - extremity sarcoma===
#[[Epithelioid sarcoma]].
#[[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=
=Adipocytic tumours=
Line 160: Line 197:


=Smooth muscle tumours=
=Smooth muscle tumours=
{{Main|Smooth muscle tumours}}
IHC markers: desmin, SMA, H-caldemsin (most specific).


==Leiomyosarcoma==
==Leiomyosarcoma==
Line 172: Line 211:


=Fibrohistiocytic tumours=
=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.<ref name=pmid20055912>{{Cite journal  | last1 = Luzar | first1 = B. | last2 = Calonje | first2 = E. | title = Cutaneous fibrohistiocytic tumours - an update. | journal = Histopathology | volume = 56 | issue = 1 | pages = 148-65 | month = Jan | year = 2010 | doi = 10.1111/j.1365-2559.2009.03447.x | PMID = 20055912 }}</ref>
==Pleomorphic undifferentiated sarcoma==
==Pleomorphic undifferentiated sarcoma==
*Abbreviated ''PUS''.
*Abbreviated ''PUS''.
*[[AKA]] ''Undifferentiated pleomorphic sarcoma''.
*[[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.
*Usu. 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.
 
Other findings:
*+/-Giant cells (see subclassification).
*+/-Inflammation (see subclassification).
**Neutrophils.
**Eosinophils.
 
Image:
*[http://commons.wikimedia.org/w/index.php?title=File:Pleomorphic_undifferentiated_sarcoma_-_very_high_mag.jpg PUS - high mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Pleomorphic_undifferentiated_sarcoma_-_intermed_mag.jpg PUS - intermed. mag. (WC)].
 
====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.


=Fibroblastic/myofibroblastic tumours=
=Fibroblastic/myofibroblastic tumours=
Line 220: Line 232:
*[[Desmoplastic fibroblastoma]].
*[[Desmoplastic fibroblastoma]].
*[[Low-grade fibromyxoid sarcoma]].
*[[Low-grade fibromyxoid sarcoma]].
*Others.


=Perivascular tumours=
=Perivascular tumours=
Line 257: Line 270:


=Tumours of uncertain differentiation=
=Tumours of uncertain differentiation=
==Extrarenal malignant rhabdoid tumour==
==Angiomatoid fibrous histiocytoma==
*Essentially identical to ''renal malignant rhabdoid tumour''.<ref name=Ref_WMSP627>{{Ref WMSP|627}}</ref>
{{Main|Angiomatoid fibrous histiocytoma}}
===General===
 
*Usu. children < 2 years old.
==Aggressive angiomyxoma==
*Very poor prognosis.
*[[AKA]] deep aggressive angiomyxoma.
*In the CNS it is known as ''[[atypical teratoid-rhabdoid tumour]]''.<ref name=Ref_WMSP627>{{Ref WMSP|627}}</ref>
{{Main|Aggressive angiomyxoma}}


===Microscopic===
==Angiomyofibroblastoma==
Features:<ref name=Ref_WMSP627>{{Ref WMSP|627}}</ref>
{{Main|Angiomyofibroblastoma}}
*Variable architecture.
*Round cells.
*Eccentric vesicular nucleus.
*Prominent [[nucleolus]] -- '''key feature'''.


===IHC===
==Extrarenal malignant rhabdoid tumour==
*INI1 (SMARCB1) -ve.
*Essentially identical to ''[[renal malignant rhabdoid tumour]]''.<ref name=Ref_WMSP627>{{Ref WMSP|627}}</ref>
**AKA BAF47.
{{Main|Extrarenal malignant rhabdoid tumour}}


==Ewing sarcoma/PNET==
==Ewing sarcoma/PNET==
Line 280: Line 289:


==Epithelioid sarcoma==
==Epithelioid sarcoma==
===General===
:Sarcomas with an epithelioid morphology are covered in ''[[epithelioid sarcomas]]''.
*Rare.
{{Main|Epithelioid sarcoma}}
*Adolescents, young adults.
 
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]].
 
===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).


==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.
 
===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.
 
Images:
*[http://commons.wikimedia.org/wiki/File:Alveolar_soft_part_sarcoma_-_low_mag.jpg ASPS - low mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Alveolar_soft_part_sarcoma_-_intermed_mag.jpg ASPS - intermed. mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Alveolar_soft_part_sarcoma_-2-_very_high_mag.jpg ASPS - very high mag. (WC)].
 
===Molecular===
*t(X;17)(p11.2;q25).<ref>{{OMIM|606243}}</ref>


==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.
 
Images:
*[http://en.wikipedia.org/wiki/File:Desmoplastic_small_round_cell_tumour_-_intermed_mag.jpg DSRCT - intermed. mag. (WC)].
*[http://en.wikipedia.org/wiki/File:Desmoplastic_small_round_cell_tumour_-_very_high_mag.jpg DSRCT - very high mag. (WC)].
 
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.
 
===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}}
**Molecular changes and origin distinct from melanoma.
*Incidence: rare soft tissue tumour.
 
===Clinical===
*Usually - deep soft tissue ''or'' extremities.
*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>
 
===Microscopy===
Features:<ref name=pmid18300804/>
*Architecture: sheets or fascicular (bundles) arrangement.
*Cells: Spindle cells or epithelioid cells.
*Prominent nucleoli - basophilic - '''key feature'''.
*Fibrous septae.
*Uniform.
*+/-Binucleation.
 
DDx:
*[[Malignant melanoma]].
*[[PEComa]].
*Carcinoma.
 
Image:
*[http://commons.wikimedia.org/wiki/File:Clear_cell_sarcoma.Image12.jpg Clear cell sarcoma (WC)].
*[http://www.informaworld.com/ampp/image?path=/713690780/789166263/sonc_a_284443_o_f0003g.jpeg Clear cell sarcoma (informaworld.com)].
 
===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.
***EWSR1-CREB1 (GI tract associated).


==Synovial sarcoma==
==Synovial sarcoma==
===General===
{{Main|Synovial sarcoma}}
*Does not arise from cartilage.<ref name=Ref_WMSP627>{{Ref WMSP|627}}</ref>
**Usually close to a joint.
**Usually distal extremity.
*Young adults or adolescents.
*Poor prognosis.
 
===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]]
*Spindle cells.
*+/-Glandular component.
 
DDx:
*[[MPNST]].
**Can be difficult.
 
Images:
*[http://commons.wikimedia.org/wiki/File:Monophasic_synovial_sarcoma_-_intermed_mag.jpg Monophasic synovial sarcoma with staghorn vessels - intermed. mag. (WC)].
*[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)].
 
===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>
 
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>PMID 6343558.</ref>
 
===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:
*SSX1.
*SSX2 - better survival
*SSX4 - uncommon.
 
Notes:
*At HSC t(X,18) = synovial sarcoma.


=Other=
=Other=
==Granulocytic sarcoma==
==Granulocytic sarcoma==
*[[AKA]] myeloid sarcoma, AKA 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.
===General===
{{Main|Granulocytic sarcoma}}
*Soft tissue manifestation of acute myeloid leukemia.
 
===Microscopic===
Features:
*May mimic small cell carcinoma, [[small round cell tumour]]s.


=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

Main article: Molecular pathology
  • 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

Main article: Chromosomal translocations

Morphohistologic patterns

Main article: Morphologic 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

Main article: Cancer staging systems

Lymph node metastases in sarcomas

Main article: Lymph node metastasis

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

Main article: Adipocytic tumours

This category includes:

  • Lipoma.
  • Liposarcoma.
  • Hibernoma.

Smooth muscle tumours

Main article: Smooth muscle tumours

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

Leiomyosarcoma

Main article: 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]
Main article: Pleomorphic undifferentiated sarcoma

Fibroblastic/myofibroblastic tumours

Main article: 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

Main article: Vascular lesions

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

They include:

Skeletal muscle tumours

Rhabdomyoma

Main article: Rhabdomyoma

Rhabdomyosarcoma

  • Abbreviated RMS.
Main article: Rhabdomyosarcoma

Comes it two main flavours:

  • Alveolar rhabdomyosarcoma.
  • Embryonal rhabdomyosarcoma.

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

Chondro-osseous tumours

Main article: Chondro-osseous tumours

This grouping includes tumours derived from cartilage and bone.

Tumours of uncertain differentiation

Angiomatoid fibrous histiocytoma

Main article: Angiomatoid fibrous histiocytoma

Aggressive angiomyxoma

  • AKA deep aggressive angiomyxoma.
Main article: Aggressive angiomyxoma

Angiomyofibroblastoma

Main article: Angiomyofibroblastoma

Extrarenal malignant rhabdoid tumour

Main article: Extrarenal malignant rhabdoid tumour

Ewing sarcoma/PNET

Main article: Ewing sarcoma

Epithelioid sarcoma

Sarcomas with an epithelioid morphology are covered in epithelioid sarcomas.
Main article: Epithelioid sarcoma

Alveolar soft part sarcoma

Main article: Alveolar soft part sarcoma

Desmoplastic small round cell tumour

Main article: Desmoplastic small round cell tumour

Clear cell sarcoma

Main article: Clear cell sarcoma

Synovial sarcoma

Main article: Synovial sarcoma

Other

Granulocytic sarcoma

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

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.
  14. ↑ URL: http://sarcomahelp.org/learning_center/mfh.html. Accessed on: 8 April 2011.
  15. ↑ Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 602. ISBN 978-0781765275.
  16. ↑ Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 627. ISBN 978-0781765275.
  17. ↑ Bakst, RL.; Tallman, MS.; Douer, D.; Yahalom, J. (Oct 2011). "How I treat extramedullary acute myeloid leukemia.". Blood 118 (14): 3785-93. doi:10.1182/blood-2011-04-347229. PMID 21795742.
  18. ↑ Eom, KS.; Kim, TY. (Mar 2011). "Intraparenchymal myeloid sarcoma and subsequent spinal myeloid sarcoma for acute myeloblastic leukemia.". J Korean Neurosurg Soc 49 (3): 171-4. doi:10.3340/jkns.2011.49.3.171. PMC 3085814. PMID 21556238. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3085814/.
Retrieved from "https://librepathology.org/w/index.php?title=Soft_tissue_lesions&oldid=41045"