Difference between revisions of "Adipocytic tumours"

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===IHC===
===IHC===
*S100 +ve.
*[[S-100]] +ve.


==Lipoblastoma==
==Lipoblastoma==
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*[http://www.sarcomaimages.com/index.php?v=Lipoblastoma Lipoblastoma (sarcomaimages.com)].
*[http://www.sarcomaimages.com/index.php?v=Lipoblastoma Lipoblastoma (sarcomaimages.com)].


==Lipoma==
==Lipoblastoma like tumor==
===General===
*Benign.
*Several variants exist.
**Angiolipoma - one of the (classically) [[painful skin lesions]].
 
===Microscopic===
Features:
*Collection of mature adipocytes.
**Variation of size may be seen -- should prompt a search for lipoblasts.<ref name=pmid8548119>{{Cite journal  | last1 = Mentzel | first1 = T. | last2 = Fletcher | first2 = CD. | title = Lipomatous tumours of soft tissues: an update. | journal = Virchows Arch | volume = 427 | issue = 4 | pages = 353-63 | month =  | year = 1995 | doi =  | PMID = 8548119 }}</ref>


Notes:
[[File: 5 22974716644038 sl 1.png|Lipoblastoma like tumor]]
*Microscopically ''not'' definitely distinguishable from mature clump of fat.
[[File: 5 22974716644038 sl 2.png|Lipoblastoma like tumor]]
**The lesion must be labeled ''lipoma'' (by the clinican) to be signed-out as such.
[[File: 5 22974716644038 sl 3.png|Lipoblastoma like tumor]]
[[File: 5 22974716644038 sl 4.png|Lipoblastoma like tumor]]


DDx:
*[[Liposarcoma]] - increased number of blood vessels,<ref name=pmid11685482>{{Cite journal  | last1 = Yang | first1 = YJ. | last2 = Damron | first2 = TA. | last3 = Cohen | first3 = H. | last4 = Hojnowski | first4 = L. | title = Distinction of well-differentiated liposarcoma from lipoma in two patients with multiple well-differentiated fatty masses. | journal = Skeletal Radiol | volume = 30 | issue = 10 | pages = 584-9 | month = Oct | year = 2001 | doi = 10.1007/s002560100395 | PMID = 11685482 }}</ref> esp. chickenwire-like vessels, fibrous septae.
*Benign adipose tissue.


Images:
Lipoblastoma like tumor in 26 yo woman, tumor of pelvis. A. Lobulated appearance at low power. B. Cytologically bland lipoblasts with a myxoid stroma. C. Numerous thin-walled branching blood vessels. D. Loose collagenous stroma. The morphologic features, combined with molecular findings of negative DDI T3 gene rearrangement and lack of MDM2 amplification permit the diagnosis.
*[http://circ.ahajournals.org/content/113/21/e778/F5.expansion.html Lipoma - cardiac (ahajournals.org)].<ref name=pmid16735681>{{Cite journal  | last1 = Friedberg | first1 = MK. | last2 = Chang | first2 = IL. | last3 = Silverman | first3 = NH. | last4 = Ramamoorthy | first4 = C. | last5 = Chan | first5 = FP. | title = Images in cardiovascular medicine. Near sudden death from cardiac lipoma in an adolescent. | journal = Circulation | volume = 113 | issue = 21 | pages = e778-9 | month = May | year = 2006 | doi = 10.1161/CIRCULATIONAHA.105.589630 | PMID = 16735681 | url = http://circ.ahajournals.org/content/113/21/e778.full }}</ref>


====Variants====
==Lipoma==
=====Angiolipoma=====
{{Main|Lipoma}}
*A [[painful skin lesions|painful skin lesion]].
 
Microscopic:
*Numerous blood vessels present.
*+/-Microthrombi.
 
DDx:
*[[Liposarcoma]].
=====Myolipoma=====
General:
*May mimic a sarcoma radiologically.<ref>URL: [http://www.webmedcentral.com/article_view/1878 http://www.webmedcentral.com/article_view/1878]. Accessed on: 14 March 2013.</ref>
*Extremely rare.<ref name=pmid15371618>{{Cite journal  | last1 = Murphey | first1 = MD. | last2 = Carroll | first2 = JF. | last3 = Flemming | first3 = DJ. | last4 = Pope | first4 = TL. | last5 = Gannon | first5 = FH. | last6 = Kransdorf | first6 = MJ. | title = From the archives of the AFIP: benign musculoskeletal lipomatous lesions. | journal = Radiographics | volume = 24 | issue = 5 | pages = 1433-66 | month =  | year =  | doi = 10.1148/rg.245045120 | PMID = 15371618 | url = http://radiographics.rsna.org/content/24/5/1433.long }}</ref>
*Usually large ~ 16 cm.<ref name=pmid1703396>{{Cite journal  | last1 = Meis | first1 = JM. | last2 = Enzinger | first2 = FM. | title = Myolipoma of soft tissue. | journal = Am J Surg Pathol | volume = 15 | issue = 2 | pages = 121-5 | month = Feb | year = 1991 | doi =  | PMID = 1703396 }}</ref>
 
Microscopic:<ref name=pmid15371618/>
*Mature adipose tissue.
*Benign smooth muscle - usually ~ 2x amount of fat.
 
Note:
*If skeletal muscle is present consider ''intramuscular lipoma''.<ref> URL: [http://surgpathcriteria.stanford.edu/softfat/lipoma/intramuscular_lipoma.html http://surgpathcriteria.stanford.edu/softfat/lipoma/intramuscular_lipoma.html]. Accessed on: 14 March 2013.</ref>
 
IHC:<ref name=pmid15371618/>
*Actin +ve.
*Desmin +ve.
 
Images:
*[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3168809/figure/F1/ Myolipoma (nih.gov)].<ref name=pmid21927569>{{Cite journal  | last1 = Lee | first1 = YS. | last2 = Park | first2 = SE. | last3 = Lee | first3 = JU. | last4 = Choi | first4 = ES. | title = MRI of a subcutaneous myolipoma in the ankle: a case report. | journal = Korean J Radiol | volume = 12 | issue = 5 | pages = 641-5 | month =  | year =  | doi = 10.3348/kjr.2011.12.5.641 | PMID = 21927569 | PMC = 3168809 }}</ref>
*[http://www.webpathology.com/image.asp?case=431&n=1 Myolipoma (webpathology.com)].
 
===Sign out===
<pre>
SUBCUTANEOUS TISSUE ("LIPOMA"), LEFT AXILLA, EXCISION:
- MATURE ADIPOSE TISSUE CONSISTENT WITH LIPOMA.
</pre>
 
<pre>
LESION ("LIPOMA"), SPERMATIC CORD (LATERALITY NOT SPECIFIED), EXCISION:
- MATURE ADIPOSE TISSUE CONSISTENT WITH LIPOMA.
</pre>
 
====Colonic lipoma (clinically suspected)====
<pre>
B. SIGMOID COLON AT 55 CM, BIOPSY:
- COLORECTAL-TYPE MUCOSA WITHIN NORMAL LIMITS WITH A SMALL AMOUNT OF SUBMUCOSAL
  ADIPOSE TISSUE; COMPATIBLE WITH CLINICAL IMPRESSION OF LIPOMA.
</pre>
 
====Mirco====
The sections show mature adipocytes.  There is no increase in vascularity.  No thick fibrous septa are present.


==Pleomorphic lipoma==
==Pleomorphic lipoma==
===General===
{{Main|Pleomorphic lipoma}}
*Rare.
*May mimic a malignancy.<ref name=pmid15510605>{{Cite journal  | last1 = Persichetti | first1 = P. | last2 = Di Lella | first2 = F. | last3 = Marangi | first3 = GF. | last4 = Cagli | first4 = B. | last5 = Simone | first5 = P. | last6 = Tenna | first6 = S. | last7 = Rabitri | first7 = C. | last8 = Cassandro | first8 = R. | last9 = Esposito | first9 = V. | title = Pleomorphic lipoma: a definite histopathological entity. | journal = Anticancer Res | volume = 24 | issue = 5B | pages = 3157-9 | month =  | year =  | doi =  | PMID = 15510605 }}</ref>
*Male > female.<ref name=pmid18181679>{{Cite journal  | last1 = Syed | first1 = S. | last2 = Martin | first2 = AM. | last3 = Haupt | first3 = H. | last4 = Podolski | first4 = V. | last5 = Brooks | first5 = JJ. | title = Frequent detection of androgen receptors in spindle cell lipomas: an explanation for this lesion's male predominance? | journal = Arch Pathol Lab Med | volume = 132 | issue = 1 | pages = 81-3 | month = Jan | year = 2008 | doi = 10.1043/1543-2165(2008)132[81:FDOARI]2.0.CO;2 | PMID = 18181679 }}</ref>
 
===Gross===
*Classically shoulder and neck region in adults.<ref>URL: [http://www.webpathology.com/image.asp?n=2&Case=435 http://www.webpathology.com/image.asp?n=2&Case=435]. Accessed on: 3 October 2011.</ref>
 
DDx - shoulder lesions:
*[[Elastofibroma]].
*[[Desmoplastic fibroblastoma]].
 
===Microscopic===
Features:
*Multinucleated cells - "floret cells" - '''key feature'''.
**Solid eosinophilic cytoplasm.
**Peripheral nuclei - impart a knobby border to the cells.
*Fibrous septa.
 
Notes:
*May overlap with ''[[spindle cell lipoma]]''.<ref name=spc_stanford>URL: [http://surgpathcriteria.stanford.edu/softfat/spindle_cell_lipoma/ http://surgpathcriteria.stanford.edu/softfat/spindle_cell_lipoma/]. Accessed on: 4 December 2010.</ref>
*Floret cell - may look similar to [[Touton giant cell]]s.
 
Images:
*[http://www.webpathology.com/image.asp?case=435&n=1 Pleomorphic lipoma - low mag. (webpathology.com)].
*[http://www.webpathology.com/image.asp?n=2&Case=435 Pleomorphic lipoma - high mag. (webpathology.com)].
 
DDx:
*[[Liposarcoma]].
*Ancient [[neurofibroma]].
*Ancient [[schwannoma]].
 
===IHC===
*AR +ve - ~95% in men, ~85% in women.<ref name=pmid18181679>{{Cite journal  | last1 = Syed | first1 = S. | last2 = Martin | first2 = AM. | last3 = Haupt | first3 = H. | last4 = Podolski | first4 = V. | last5 = Brooks | first5 = JJ. | title = Frequent detection of androgen receptors in spindle cell lipomas: an explanation for this lesion's male predominance? | journal = Arch Pathol Lab Med | volume = 132 | issue = 1 | pages = 81-3 | month = Jan | year = 2008 | doi = 10.1043/1543-2165(2008)132[81:FDOARI]2.0.CO;2 | PMID = 18181679 }}</ref>


==Spindle cell lipoma==
==Spindle cell lipoma==
===General===
{{Main|Spindle cell lipoma}}
*Rare.
*Predominantly men.<ref name=pmid15371618/>
 
Note:
*Spindle cell lipoma may immunohistochemically and histomorphologically overlap with ''mammary-type myofibroblastoma''<ref name=pmid11474286>{{Cite journal  | last1 = McMenamin | first1 = ME. | last2 = Fletcher | first2 = CD. | title = Mammary-type myofibroblastoma of soft tissue: a tumor closely related to spindle cell lipoma. | journal = Am J Surg Pathol | volume = 25 | issue = 8 | pages = 1022-9 | month = Aug | year = 2001 | doi =  | PMID = 11474286 }}</ref> - see: ''[[mammary myofibroblastoma]]''.
 
===Microscopic===
Features:<ref name=pmid15371618>{{Cite journal  | last1 = Murphey | first1 = MD. | last2 = Carroll | first2 = JF. | last3 = Flemming | first3 = DJ. | last4 = Pope | first4 = TL. | last5 = Gannon | first5 = FH. | last6 = Kransdorf | first6 = MJ. | title = From the archives of the AFIP: benign musculoskeletal lipomatous lesions. | journal = Radiographics | volume = 24 | issue = 5 | pages = 1433-66 | month =  | year =  | doi = 10.1148/rg.245045120 | PMID = 15371618 }}</ref>
*Aligned bland spindled cells adjacent to fat.
*Rope-like collagen bundles - '''key feature'''.
**May be described as "shreaded wheat".
*+/-[[Myxoid]] component.
*+/-[[staghorn vessels|Staghorn-like vessels]].
 
Notes:
*May overlap with ''[[pleomorphic lipoma]]''.<ref name=spc_stanford>URL: [http://surgpathcriteria.stanford.edu/softfat/spindle_cell_lipoma/ http://surgpathcriteria.stanford.edu/softfat/spindle_cell_lipoma/]. Accessed on: 4 December 2010.</ref>
 
DDx:
*[[Neurofibroma]].
*Spindle cell liposarcoma - extremely rare.<ref name=pmid8067512>{{Cite journal  | last1 = Dei Tos | first1 = AP. | last2 = Mentzel | first2 = T. | last3 = Newman | first3 = PL. | last4 = Fletcher | first4 = CD. | title = Spindle cell liposarcoma, a hitherto unrecognized variant of liposarcoma. Analysis of six cases. | journal = Am J Surg Pathol | volume = 18 | issue = 9 | pages = 913-21 | month = Sep | year = 1994 | doi =  | PMID = 8067512 }}</ref>
 
====Image====
www:
*[http://www.sarcoma.org/pathology_review/round%20cell%20and%20soft%20tissue%20tumors/source/spindle_cell_lipoma3.html Spindle cell lipoma (sarcoma.org)].
 
===IHC===
*CD34 +ve.<ref name=pmid20559119>{{Cite journal  | last1 = Wood | first1 = L. | last2 = Fountaine | first2 = TJ. | last3 = Rosamilia | first3 = L. | last4 = Helm | first4 = KF. | last5 = Clarke | first5 = LE. | title = Cutaneous CD34+ spindle cell neoplasms: Histopathologic features distinguish spindle cell lipoma, solitary fibrous tumor, and dermatofibrosarcoma protuberans. | journal = Am J Dermatopathol | volume = 32 | issue = 8 | pages = 764-8 | month = Dec | year = 2010 | doi = 10.1097/DAD.0b013e3181d0c587 | PMID = 20559119 }}</ref>
*Desmin +ve.
*S100 -ve. (???)


==Hibernoma==
==Hibernoma==
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==Atypical lipomatous tumour==
==Atypical lipomatous tumour==
*[[AKA]] ''well-differentiated liposarcoma'', abbreviated ''WDLPS''.
*[[AKA]] ''well-differentiated liposarcoma'', abbreviated ''WDLPS''.<ref name=pmid24659226>{{Cite journal  | last1 = Creytens | first1 = D. | last2 = van Gorp | first2 = J. | last3 = Savola | first3 = S. | last4 = Ferdinande | first4 = L. | last5 = Mentzel | first5 = T. | last6 = Libbrecht | first6 = L. | title = Atypical spindle cell lipoma: a clinicopathologic, immunohistochemical, and molecular study emphasizing its relationship to classical spindle cell lipoma. | journal = Virchows Arch | volume = 465 | issue = 1 | pages = 97-108 | month = Jul | year = 2014 | doi = 10.1007/s00428-014-1568-8 | PMID = 24659226 }}</ref>
*Abbreviated ''ALT/WDLPS''.
*Abbreviated ''ALT/WDLPS''.


Line 221: Line 98:


==Liposarcoma==
==Liposarcoma==
{{Main|Liposarcoma}}
==Angiolipoma==
===General===
===General===
*Most common malignant sarcoma in the retroperitoneum.
*May be syndromic - typically [[autosomal recessive]].<ref name=pmid25671454>{{cite journal |authors=Garib G, Siegal GP, Andea AA |title=Autosomal-dominant familial angiolipomatosis |journal=Cutis |volume=95 |issue=1 |pages=E26–9 |date=January 2015 |pmid=25671454 |doi= |url=}}</ref>
*Not all (large) retroperitoneal adipocytic tumours are liposarcomas.
*Can be seen in the context of [[Birt–Hogg–Dubé syndrome]].<ref name=pmid8734663>{{cite journal |authors=Chung JY, Ramos-Caro FA, Beers B, Ford MJ, Flowers F |title=Multiple lipomas, angiolipomas, and parathyroid adenomas in a patient with Birt-Hogg-Dube syndrome |journal=Int J Dermatol |volume=35 |issue=5 |pages=365–7 |date=May 1996 |pmid=8734663 |doi=10.1111/j.1365-4362.1996.tb03642.x |url=}}</ref>
 
*[[Painful skin lesion]].
Notes:
*Retroperitoneal sarcomas: #1: liposarcoma, #2: [[pleomorphic undifferentiated sarcoma]], #3: leiomyosarcoma, #4: [[MPNST]].
**Extremely rare in retroperitoneum: [[synovial sarcoma]].


===Microscopic===
===Microscopic===
Features:
Features:
*Lipoblasts - '''key feature'''.
*Adipose tissue.
**Large sharply demarcated vacuole.
*Small blood vessels (clustered).
**Nucleus:
***Hyperchromatic (dark staining) nucleus.
***Eccentric location.
***Nuclear indentation.
*Chicken wire-like vascular.
*+/-[[Myxoid]] background.
*Cell size variation.


DDx:
DDx:
*[[Angiolipoma]].
*[[Liposarcoma]].
*[[Pleomorphic undifferentiated sarcoma]].
 
Images:
*[http://commons.wikimedia.org/wiki/File:Myxoid_liposarcoma_%2806%29.JPG Myxoid liposarcoma (WC)].
*[http://commons.wikimedia.org/wiki/File:Myxoid_liposarcoma_%2805%29.JPG Myxoid liposarcoma (WC)].
*[http://www.john-libbey-eurotext.fr/e-docs/00/04/09/14/texte_alt_jleejd00046_gr5.jpg Lipoblasts (john-libbey-eurotext.fr)].
*[http://commons.wikimedia.org/wiki/File:Dedifferentiated_liposarcoma_-_cropped_-_very_high_mag.jpg Dediff. liposarcoma - lipoblasts - very high mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Dedifferentiated_liposarcoma_-_intermed_mag.jpg Dediff. liposarcoma - shows dediff. component - intermed. mag. (WC)].
*[http://path.upmc.edu/cases/case302.html Poorly diff. liposarcoma - several images (upmc.edu)].
 
====Subtypes====
Main subtypes:<ref name=Ref_WMSP_601>{{Ref WMSP|601}}</ref>
*Dedifferentiated liposarcoma.
*Myxoid liposarcoma.
**Round cell liposarcoma - a subtype of myxoid liposarcoma<ref name=pmid8554106>{{Cite journal  | last1 = Smith | first1 = TA. | last2 = Easley | first2 = KA. | last3 = Goldblum | first3 = JR. | title = Myxoid/round cell liposarcoma of the extremities. A clinicopathologic study of 29 cases with particular attention to extent of round cell liposarcoma. | journal = Am J Surg Pathol | volume = 20 | issue = 2 | pages = 171-80 | month = Feb | year = 1996 | doi =  | PMID = 8554106 }}
</ref> that has a worse prognosis;<ref name=pmid21253554>{{Cite journal  | last1 = Conyers | first1 = R. | last2 = Young | first2 = S. | last3 = Thomas | first3 = DM. | title = Liposarcoma: molecular genetics and therapeutics. | journal = Sarcoma | volume = 2011 | issue =  | pages = 483154 | month =  | year = 2011 | doi = 10.1155/2011/483154 | PMID = 21253554 }}</ref> characterized by regions of high cellularity.
*Mixed-type liposarcoma.
*Pleomorphic liposarcoma.
*Liposarcoma not otherwise specified (NOS).
 
Additional reported type:
*Spindle cell liposarcoma.<ref name=pmid8067512>{{Cite journal  | last1 = Dei Tos | first1 = AP. | last2 = Mentzel | first2 = T. | last3 = Newman | first3 = PL. | last4 = Fletcher | first4 = CD. | title = Spindle cell liposarcoma, a hitherto unrecognized variant of liposarcoma. Analysis of six cases. | journal = Am J Surg Pathol | volume = 18 | issue = 9 | pages = 913-21 | month = Sep | year = 1994 | doi =  | PMID = 8067512 }}</ref>
=====Myxoid liposarcoma=====
*[[AKA]] ''myxoid/round cell liposarcoma''.
*[[AKA]] ''round cell liposarcoma''.
 
======Gross======
Location:<ref name=pmid22052112>{{Cite journal  | last1 = Moreau | first1 = LC. | last2 = Turcotte | first2 = R. | last3 = Ferguson | first3 = P. | last4 = Wunder | first4 = J. | last5 = Clarkson | first5 = P. | last6 = Masri | first6 = B. | last7 = Isler | first7 = M. | last8 = Dion | first8 = N. | last9 = Werier | first9 = J. | title = Myxoid\Round Cell Liposarcoma (MRCLS) Revisited: An Analysis of 418 Primarily Managed Cases. | journal = Ann Surg Oncol | volume = 19 | issue = 4 | pages = 1081-1088 | month = Apr | year = 2012 | doi = 10.1245/s10434-011-2127-z | PMID = 22052112 }}</ref>
*90% in lower limb.
*81% deep.
 
======Microscopic======
Features:
*Chickenwire-type blood vessels.
*Clear spaces.
*Adipocytes - may be rare.
 
DDx:
*[[Low-grade fibromyxoid sarcoma]].
 
Images:
*[http://radiographics.rsna.org/content/20/4/1007/F4.expansion.html Myxoid liposarcoma (rsna.org)].
*[http://www.cap.org/apps/cap.portal?_nfpb=true&cntvwrPtlt_actionOverride=%2Fportlets%2FcontentViewer%2Fshow&_windowLabel=cntvwrPtlt&cntvwrPtlt{actionForm.contentReference}=cap_foundation%2FcaseOfMonth%2Ffeb13%2Ffeb_2013_cotm_diagnosis.html&_state=maximized&_pageLabel=cntvwr Myxoid liposarcoma (cap.org)].
 
======Molecular======
Typically has a [[translocations|translocation]]:
*t(12;16)(q13;p11) TLS-CHOP.<ref name=pmid7805034>{{Cite journal  | last1 = Knight | first1 = JC. | last2 = Renwick | first2 = PJ. | last3 = Dal Cin | first3 = P. | last4 = Van den Berghe | first4 = H. | last5 = Fletcher | first5 = CD. | title = Translocation t(12;16)(q13;p11) in myxoid liposarcoma and round cell liposarcoma: molecular and cytogenetic analysis. | journal = Cancer Res | volume = 55 | issue = 1 | pages = 24-7 | month = Jan | year = 1995 | doi =  | PMID = 7805034 }}</ref>
*May have the translocation usually seen in [[clear cell sarcoma]]:
*t(12;22)(q13;q12) EWS-ATF1.<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>
 
=====Dedifferentiated liposarcoma=====
*Has an undifferentiated component that, if seen alone, would be diagnosed as [[pleomorphic undifferentiated sarcoma]].
*The diagnosis depends on the presence of the differentiated component of the tumour, i.e. the presence of lipoblasts.
 
===IHC===
*IHC is of limited value.
 
*S-100 +ve ~1/3 of the time.
*Reticulin ???.


=See also=
=See also=
*[[Soft tissue lesions]].
*[[Soft tissue lesions]].
*[[Bone]].
*[[Bone]].
*[[Brown fat]].


=References=
=References=

Latest revision as of 15:51, 22 April 2024

Adipocytic tumours fall into the grouping soft tissue lesions and includes things that are very common (e.g. lipoma) and everything from benign to malignant.

Overview

This grouping includes a number of tumours, which can be divided based on their behaviour into benign, intermediate and malignant.

Benign

Benign adipocytic tumours:[1]

Intermediate

Intermediate adipocytic tumours:[1]

  • Atypical lipomatous tumour.

Malignant

Malignant adipocytic tumours:[1]

  • Dedifferentiated liposarcoma.
  • Myxoid liposarcoma.
  • Pleomorphic liposarcoma.
  • Mixed-type liposarcoma.
  • Liposarcoma NOS.

Detail section

Normal mature fat

Microscopic

Features:

  • Adipocytes of approximately equal size.
  • Not vascular.
  • No nuclear hyperchromasia.

Notes:

  • May have nuclear pseudoinclusions (Lockhern cell).[2]
    • There is some suggestion this is not benign.[3]

IHC

Lipoblastoma

General

  • Rare paediatric tumour.[4]

Usual presentation:[4]

  • Painless neck mass.

Microscopic

Features:

  • Nests of cells in the dermis with abundant pale cytoplasm - vaguely resemble adipocytes.
    • Smaller than mature adipocytes.

DDx:

Images:

Lipoblastoma like tumor

Lipoblastoma like tumor Lipoblastoma like tumor Lipoblastoma like tumor Lipoblastoma like tumor


Lipoblastoma like tumor in 26 yo woman, tumor of pelvis. A. Lobulated appearance at low power. B. Cytologically bland lipoblasts with a myxoid stroma. C. Numerous thin-walled branching blood vessels. D. Loose collagenous stroma. The morphologic features, combined with molecular findings of negative DDI T3 gene rearrangement and lack of MDM2 amplification permit the diagnosis.

Lipoma

Pleomorphic lipoma

Spindle cell lipoma

Hibernoma

Atypical lipomatous tumour

  • AKA well-differentiated liposarcoma, abbreviated WDLPS.[6]
  • Abbreviated ALT/WDLPS.

General

  • Atypical lipomatous tumour is a term used to save people with a (curable) peripheral liposarcoma from getting denied life insurance.

Microscopic

Features:[7]

  • Large adipocytes.
  • Atypical lipoblasts - focal, scattered:
    • Nuclear hyperchromasia.
    • +/-Multinucleated.

Liposarcoma

Angiolipoma

General

Microscopic

Features:

  • Adipose tissue.
  • Small blood vessels (clustered).

DDx:

See also

References

  1. 1.0 1.1 1.2 Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 601. ISBN 978-0781765275.
  2. URL: http://journals.lww.com/amjdermatopathology/Citation/2004/12000/Original_Observation_to_Rediscovery__Nuclear.9.aspx. Accessed on: 18 April 2011.
  3. URL: http://www.pathconsultddx.com/pathCon/diagnosis?pii=S1559-8675%2806%2970574-5. Accessed on: 18 April 2011.
  4. 4.0 4.1 Pham, NS.; Poirier, B.; Fuller, SC.; Dublin, AB.; Tollefson, TT. (Jul 2010). "Pediatric lipoblastoma in the head and neck: a systematic review of 48 reported cases.". Int J Pediatr Otorhinolaryngol 74 (7): 723-8. doi:10.1016/j.ijporl.2010.04.010. PMID 20472310.
  5. Nagano, A.; Ohno, T.; Nishimoto, Y.; Hirose, Y.; Miyake, S.; Shimizu, K. (2011). "Lipoblastoma mimicking myxoid liposarcoma: a clinical report and literature review.". Tohoku J Exp Med 223 (1): 75-8. PMID 21212605.
  6. Creytens, D.; van Gorp, J.; Savola, S.; Ferdinande, L.; Mentzel, T.; Libbrecht, L. (Jul 2014). "Atypical spindle cell lipoma: a clinicopathologic, immunohistochemical, and molecular study emphasizing its relationship to classical spindle cell lipoma.". Virchows Arch 465 (1): 97-108. doi:10.1007/s00428-014-1568-8. PMID 24659226.
  7. Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 605. ISBN 978-0781765275.
  8. Garib G, Siegal GP, Andea AA (January 2015). "Autosomal-dominant familial angiolipomatosis". Cutis 95 (1): E26–9. PMID 25671454.
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