Charli-Joseph Y, Saggini A, Vemula S, Weier J, Mirza S, LeBoit PE. Primary cutaneous perivascular epithelioid cell tumor: a clinicopathological and molecular reappraisal.
J Am Acad Dermatol 2014;
71:1127-36. [PMID:
25267378 DOI:
10.1016/j.jaad.2014.08.016]
[Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 08/02/2014] [Accepted: 08/10/2014] [Indexed: 01/20/2023]
Abstract
BACKGROUND
Perivascular epithelioid cell tumor (PEComa) is a rare neoplasm of uncertain histogenesis with a mixed myomelanocytic immunophenotype, rarely arising in the skin (primary cutaneous PEComa [pcPEComa]).
OBJECTIVE
We analyzed the clinicopathological features of 8 pcPEComas, assayed for DNA copy number changes and for initiating mutations common in melanocytic neoplasms.
METHODS
pcPEComas were evaluated using immunohistochemistry, comparative genomic hybridization, and DNA sequencing.
RESULTS
pcPEComas were erythematous nodules, mostly in the lower extremities of women (5/8), composed of large pale-staining epithelioid cells. The patient's age range was 26 to 67 (mean 46) years. The percentages of tumors staining positively were as follows: micro-ophthalmia-associated transcription factor, NKI/C3, bcl-1, E-cadherin, and cathepsin K (100%); HMB-45, 4E-binding protein 1, and CD68 (88%); smooth muscle actin and muscle-specific actin (40%); S100 (38%); calponin (20%); desmin (13%); and melan-A, SOX10, and keratin (0%). No chromosomal copy number changes or initiating mutations were identified.
LIMITATIONS
Small sample size is a limitation.
CONCLUSIONS
pcPEComas have a different molecular signature than extracutaneous tumors and are unrelated to tuberous sclerosis. However, the common expression of 4E-binding protein 1 points to a role of the mTOR pathway in their pathogenesis. Because pcPEComas are diagnostically challenging, we propose that micro-ophthalmia-associated transcription factor, NKIC3, smooth muscle actin, desmin, bcl-1, cathepsin K, and 4E-binding protein 1 can be used when evaluating a possible pcPEComa.
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