Adipocytic tumours

From Libre Pathology
Revision as of 01:40, 31 October 2013 by Michael (talk | contribs) (→‎Lipoma: split-out)
Jump to navigation Jump to search

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

  • S100 +ve.

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:

Lipoma

Main article: Lipoma

Pleomorphic lipoma

General

  • Rare.
  • May mimic a malignancy.[6]
  • Male > female.[7]

Gross

  • Classically shoulder and neck region in adults.[8]

DDx - shoulder lesions:

Microscopic

Features:

  • Multinucleated cells - "floret cells" - key feature.
    • Solid eosinophilic cytoplasm.
    • Peripheral nuclei - impart a knobby border to the cells.
  • Fibrous septa.

Notes:

Images:

DDx:

IHC

  • AR +ve - ~95% in men, ~85% in women.[7]

Spindle cell lipoma

General

  • Rare.
  • Predominantly men.[10]

Note:

  • Spindle cell lipoma may immunohistochemically and histomorphologically overlap with mammary-type myofibroblastoma[11] - see: mammary myofibroblastoma.

Microscopic

Features:[10]

  • Aligned bland spindled cells adjacent to fat.
  • Rope-like collagen bundles - key feature.
    • May be described as "shreaded wheat".
  • +/-Myxoid component.
  • +/-Staghorn-like vessels.

Notes:

DDx:

Image

www:

IHC

  • CD34 +ve.[13]
  • Desmin +ve.
  • S100 -ve. (???)

Hibernoma

Main article: Hibernoma

Atypical lipomatous tumour

  • AKA well-differentiated liposarcoma, abbreviated WDLPS.
  • 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:[14]

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

Liposarcoma

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[15] that has a worse prognosis;[16] characterized by regions of high cellularity.
  • Mixed-type liposarcoma.
  • Pleomorphic liposarcoma.
  • Liposarcoma not otherwise specified (NOS).

Additional reported type:

  • Spindle cell liposarcoma.[12]
Myxoid liposarcoma
  • AKA myxoid/round cell liposarcoma.
  • AKA round cell liposarcoma.
Gross

Location:[17]

  • 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:

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. ↑ 1.0 1.1 1.2 1.3 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. ↑ Persichetti, P.; Di Lella, F.; Marangi, GF.; Cagli, B.; Simone, P.; Tenna, S.; Rabitri, C.; Cassandro, R. et al. "Pleomorphic lipoma: a definite histopathological entity.". Anticancer Res 24 (5B): 3157-9. PMID 15510605.
  7. ↑ 7.0 7.1 Syed, S.; Martin, AM.; Haupt, H.; Podolski, V.; Brooks, JJ. (Jan 2008). "Frequent detection of androgen receptors in spindle cell lipomas: an explanation for this lesion's male predominance?". Arch Pathol Lab Med 132 (1): 81-3. doi:10.1043/1543-2165(2008)132[81:FDOARI]2.0.CO;2. PMID 18181679.
  8. ↑ URL: http://www.webpathology.com/image.asp?n=2&Case=435. Accessed on: 3 October 2011.
  9. ↑ 9.0 9.1 URL: http://surgpathcriteria.stanford.edu/softfat/spindle_cell_lipoma/. Accessed on: 4 December 2010.
  10. ↑ 10.0 10.1 Murphey, MD.; Carroll, JF.; Flemming, DJ.; Pope, TL.; Gannon, FH.; Kransdorf, MJ.. "From the archives of the AFIP: benign musculoskeletal lipomatous lesions.". Radiographics 24 (5): 1433-66. doi:10.1148/rg.245045120. PMID 15371618.
  11. ↑ McMenamin, ME.; Fletcher, CD. (Aug 2001). "Mammary-type myofibroblastoma of soft tissue: a tumor closely related to spindle cell lipoma.". Am J Surg Pathol 25 (8): 1022-9. PMID 11474286.
  12. ↑ 12.0 12.1 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.
  13. ↑ Wood, L.; Fountaine, TJ.; Rosamilia, L.; Helm, KF.; Clarke, LE. (Dec 2010). "Cutaneous CD34+ spindle cell neoplasms: Histopathologic features distinguish spindle cell lipoma, solitary fibrous tumor, and dermatofibrosarcoma protuberans.". Am J Dermatopathol 32 (8): 764-8. doi:10.1097/DAD.0b013e3181d0c587. PMID 20559119.
  14. ↑ 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.
  15. ↑ 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.
  16. ↑ Conyers, R.; Young, S.; Thomas, DM. (2011). "Liposarcoma: molecular genetics and therapeutics.". Sarcoma 2011: 483154. doi:10.1155/2011/483154. PMID 21253554.
  17. ↑ 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.
  18. ↑ 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.
  19. ↑ 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.
Retrieved from "https://librepathology.org/w/index.php?title=Adipocytic_tumours&oldid=25343"