Transcription factor E3 protein-positive perivascular epithelioid cell tumor of the appendix presenting as acute appendicitis: A case report and review of the literature

Kristina A. Matkowskyj, M. Sambasiva Rao, Kirtee Raparia*

*Corresponding author for this work

Research output: Contribution to journalReview article


Perivascular epithelioid cell tumors (PEComas) are a group of mesenchymal tumors that coexpress melanocytic and smooth muscle markers; their exact origin remains unknown. This group includes renal angiomyolipoma, clear cell sugar tumor, and lymphangioleiomyomatosis, although the term perivascular epithelioid cell tumors is currently used for lesions that exhibit a similar morphologic and immunohistochemical profile throughout the human body. Recently, a distinct subset of PEComas has been shown to harbor transcription factor E3 gene (TFE3) fusions. We report, for the first time, a unique case of TFE3-positive PEComa presenting as acute appendicitis in a 24-year-old woman. Microscopically, the tumor was composed of benign-appearing epithelioid cells with clear and eosinophilic cytoplasm, and arranged in nested and alveolar patterns. Immunohistochemical studies showed diffuse strong positivity for neuron-specific enolase, TFE3, and progesterone receptor and focal strong positivity for human melanoma black-45 (HMB-45) and melanocyte differentiation antigen (Melan-A) in the tumor cells. Although rare, PEComa should be included in the differential diagnosis of mesenchymal tumors of the appendix.

Original languageEnglish (US)
Pages (from-to)434-437
Number of pages4
JournalArchives of Pathology and Laboratory Medicine
Issue number3
StatePublished - Mar 1 2013


ASJC Scopus subject areas

  • Pathology and Forensic Medicine
  • Medical Laboratory Technology

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