Colon tumor
Mesenchymal tumors
Perivascular epithelioid cell tumor

Topic Completed: 1 May 2017

Revised: 9 July 2019

Copyright: 2003-2019,, Inc.

PubMed search: colonic perivascular epithelioid cell tumor

Raul S. Gonzalez, M.D.
Page views in 2019: 677
Page views in 2020 to date: 78
Cite this page: Gonzalez R. Perivascular epithelioid cell tumor. website. Accessed February 27th, 2020.
Definition / general
  • Mesenchymal neoplasm with melanocytic and smooth muscle features
Essential features
  • Also called PEComa
Clinical features
Case reports
Clinical images

Images hosted on other servers:

CT scan showing a cecal PEComa

Gross images

Images hosted on other servers:

Large cecal mass

Microscopic (histologic) description
  • Tumor can exist anywhere within the wall; most commonly involves serosa/subserosa
  • Sheets/nests of epithelioid cells with clear or eosinophilic cytoplasm
  • Some tumors may show partially or predominantly spindled cells
  • Tumor necrosis, vascular invasion, and occasional mitoses often present
  • Metastatic lesions show more severe atypia and mitotic rates
Microscopic (histologic) images

Images hosted on other servers:

Low power

High power

HMB45 staining

Positive stains
Negative stains
Differential diagnosis
Board review style question #1
A 15 year old girl develops anemia and abdominal pain. Workup identifies a 7 cm cecal mass that is resected. On H&E examination, the pathologist suspects the lesion may be a perivascular epithelioid cell tumor. What immunohistochemical markers would be positive in this lesion, to confirm the diagnosis?

A. Neural and melanocytic markers
B. Neural and skeletal muscle markers
C. Neural and smooth muscle markers
D. Skeletal muscle and melanocytic markers
E. Smooth muscle and melanocytic markers
Board review answer #1
E. Smooth muscle and melanocytic markers

Reference: Colon tumor - Perivascular epithelioid cell tumor

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