Primary cutaneous perivascular epithelioid cell tumor: A clinicopathological and molecular reappraisal - 15/11/14
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.
Le texte complet de cet article est disponible en PDF.Key words : array-based comparative genomic hybridization, cutaneous clear cell myomelanocytic tumor, initiating mutations, mTOR pathway, perivascular epithelioid cell tumor
Abbreviations used : aCGH, MiTF, pcPEComa, PEComa, SMA, TSC, 4EBP1
Plan
Funding sources: None. |
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Conflicts of interest: None declared. |
Vol 71 - N° 6
P. 1127-1136 - décembre 2014 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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