Liposarcoma

From Libre Pathology
Revision as of 00:28, 6 January 2014 by Michael (talk | contribs) (split out)
Jump to navigation Jump to search

Liposarcoma is a malignant adipocytic tumour.

General

  • Most common malignant sarcoma in the retroperitoneum.
  • Not all (large) retroperitoneal adipocytic tumours are liposarcomas.

Notes:

Microscopic

Features:

  • Lipoblasts - key feature.
    • Large sharply demarcated vacuole.
    • Nucleus:
      • Hyperchromatic (dark staining) nucleus.
      • Eccentric location.
      • Nuclear indentation.
  • Chicken wire-like vascular.
  • +/-Myxoid background.
  • Cell size variation.

DDx:

Images:

Subtypes

Main subtypes:[1]

  • Dedifferentiated liposarcoma.
  • Myxoid liposarcoma.
    • Round cell liposarcoma - a subtype of myxoid liposarcoma[2] that has a worse prognosis;[3] characterized by regions of high cellularity.
  • Mixed-type liposarcoma.
  • Pleomorphic liposarcoma.
  • Liposarcoma not otherwise specified (NOS).

Additional reported type:

  • Spindle cell liposarcoma.[4]

Myxoid liposarcoma

  • AKA myxoid/round cell liposarcoma.
  • AKA round cell liposarcoma.
Gross

Location:[5]

  • 90% in lower limb.
  • 81% deep.
Microscopic

Features:

  • Chickenwire-type blood vessels.
  • Clear spaces.
  • Adipocytes - may be rare.

DDx:

Images:

Molecular

Typically has a translocation:

  • t(12;16)(q13;p11) TLS-CHOP.[8]
  • May have the translocation usually seen in clear cell sarcoma:
  • t(12;22)(q13;q12) EWS-ATF1.[9]

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

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. ISBN 978-0781765275.
  2. Smith, TA.; Easley, KA.; Goldblum, JR. (Feb 1996). "Myxoid/round cell liposarcoma of the extremities. A clinicopathologic study of 29 cases with particular attention to extent of round cell liposarcoma.". Am J Surg Pathol 20 (2): 171-80. PMID 8554106.
  3. Conyers, R.; Young, S.; Thomas, DM. (2011). "Liposarcoma: molecular genetics and therapeutics.". Sarcoma 2011: 483154. doi:10.1155/2011/483154. PMID 21253554.
  4. Dei Tos, AP.; Mentzel, T.; Newman, PL.; Fletcher, CD. (Sep 1994). "Spindle cell liposarcoma, a hitherto unrecognized variant of liposarcoma. Analysis of six cases.". Am J Surg Pathol 18 (9): 913-21. PMID 8067512.
  5. Moreau, LC.; Turcotte, R.; Ferguson, P.; Wunder, J.; Clarkson, P.; Masri, B.; Isler, M.; Dion, N. et al. (Apr 2012). "Myxoid\Round Cell Liposarcoma (MRCLS) Revisited: An Analysis of 418 Primarily Managed Cases.". Ann Surg Oncol 19 (4): 1081-1088. doi:10.1245/s10434-011-2127-z. PMID 22052112.
  6. Sung, MS.; Kang, HS.; Suh, JS.; Lee, JH.; Park, JM.; Kim, JY.; Lee, HG.. "Myxoid liposarcoma: appearance at MR imaging with histologic correlation.". Radiographics 20 (4): 1007-19. doi:10.1148/radiographics.20.4.g00jl021007. PMID 10903690.
  7. Murphey, MD.; Arcara, LK.; Fanburg-Smith, J.. "From the archives of the AFIP: imaging of musculoskeletal liposarcoma with radiologic-pathologic correlation.". Radiographics 25 (5): 1371-95. doi:10.1148/rg.255055106. PMID 16160117.
  8. Knight, JC.; Renwick, PJ.; Dal Cin, P.; Van den Berghe, H.; Fletcher, CD. (Jan 1995). "Translocation t(12;16)(q13;p11) in myxoid liposarcoma and round cell liposarcoma: molecular and cytogenetic analysis.". Cancer Res 55 (1): 24-7. PMID 7805034.
  9. Suzuki, K.; Matsui, Y.; Endo, K.; Kubo, T.; Hasegawa, T.; Kimura, T.; Ohtani, O.; Yasui, N. (Nov 2010). "Myxoid liposarcoma with EWS-CHOP type 1 fusion gene.". Anticancer Res 30 (11): 4679-83. PMID 21115923.