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Malignant perivascular epithelioid cell tumor of the colon: Report of a case with molecular analysis
Author(s) -
Yamamoto Hidetaka,
Oda Yoshinao,
Yao Takashi,
Oiwa Toshio,
Kobayashi Chikashi,
Tamiya Sadafumi,
Kawaguchi Kenichi,
Hino Okio,
Tsuneyoshi Masazumi
Publication year - 2006
Publication title -
pathology international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.73
H-Index - 74
eISSN - 1440-1827
pISSN - 1320-5463
DOI - 10.1111/j.1440-1827.2006.01917.x
Subject(s) - perivascular epithelioid cell , pathology , tuberous sclerosis , tsc1 , epithelioid cell , immunohistochemistry , angiomyolipoma , eosinophilic , hmb 45 , loss of heterozygosity , biology , medicine , kidney , gene , apoptosis , biochemistry , allele , pi3k/akt/mtor pathway
Perivascular epithelioid cell tumor (PEComa) is a rare mesenchymal neoplasm, and malignant cases are extremely rare. A case of malignant PEComa arising in the colon is described herein. The patient was a 43‐year‐old Japanese woman without a history of tuberous sclerosis complex. The tumor occurred in the abdominal cavity attached to the serosal side of the descending colon. Histologically, the tumor consisted of sheets or closely packed nests of epithelioid cells with clear or eosinophilic cytoplasms. The tumor cells were positive for HMB‐45 but negative for S‐100 protein and cytokeratins by immunohistochemical staining. Ki‐67 labeling index was 2.9%. Peritoneal dissemination of tumor occurred at 20 months and the patient died of tumor at 38 months after the initial operation. This was considered to be a case of malignant PEComa, based on the histological and clinical features. Tumor cells showed overexpression of cyclin D1 but lacked the loss of heterozygosity of the TSC1 and TSC2 genes. The result suggests that the overexpression of cyclin D1 may play an important role in the tumorigenesis of PEComa. Because PEComas can behave in an aggressive manner, careful follow up is warranted.