title: Perivascular epithelioid cell neoplasm of the colon.
abstract: A 17-year-old female presented with rectal bleeding from an ulcerated sigmoid mass in 1994. Initial pathological evaluation revealed a rare clear cell neoplasm of the colon, possibly originating from kidneys, adrenals, lung or a gynecologic source as a metastatic lesion. Extensive imaging studies were negative, and over the next 15 years, she remained well with no recurrence. The original resected neoplasm was reviewed and re-classified as a perivascular epithelioid cell neoplasm (PEComa). Although the long-term natural history of PEComas requires definition, increased clinical and pathological awareness should lead to increased recognition of an apparently rare type of colonic neoplasm that likely occurs more often than is currently appreciated.
authors.affiliation: Hugh James Freeman, Department of Medicine (Gastroenterology), University of British Columbia, Vancouver BC V6T 1W5, Canada.
authors.forename: Hugh James
authors.initials: HJ
authors.lastname: Freeman
authors.forename: Doug L
authors.initials: DL
authors.lastname: Webber