title: Perivascular epithelioid cell tumor of gastrointestinal tract: case report and review of the literature.
abstract: Perivascular epithelioid cell tumors of gastrointestinal tract (GI PEComas) are exceedingly rare, with only a limited number of published reports worldwide. Given the scarcity of GI PEComas and their relatively short follow-up periods, our current knowledge of their biologic behavior, molecular genetic alterations, diagnostic criteria, and prognostic factors continues to be very limited.We present 2 cases of GI PEComas, one of which showed an aggressive histologic behavior that underwent multiple combined chemotherapies. We also review the available English-language medical literature on GI PEComas-not otherwise specified (PEComas-NOS) and discuss their clinicopathological and molecular genetic features.Pathologic analyses including histomorphologic, immunohistochemical, and ultrastructural studies were performed to evaluate the clinicopathological features of GI PEComas, their diagnosis, and differential diagnosis. Immunohistochemistry, semiquantitative reverse transcriptase polymerase chain reaction, and DNA sequencing assays were carried out to detect the potential molecular genetic alterations in our cases. Microscopically, the tumors showed distinctive histologic features of PEComas-NOS, including fascicular or nested architecture, epithelioid or spindled cell type, and clear to eosinophilic cytoplasm. The tumor cells were immunohistochemically positive for melanocytic markers. Molecular pathological assays confirmed a PSF-TFE3 gene fusion in one of our cases. Furthermore, in this case microphthalmia-associated transcription factor and its downstream genes were found to exhibit elevated transcript levels.Knowledge about the molecular genetic alterations in GI PEComas is still limited and warrants further study.
authors.affiliation: From the Guangdong Institute of Gastroenterology and the Sixth Affiliated Hospital, (BL, CW, JZ, MS, XZ, SS, JW, HL); Guangdong Key Laboratory of Colorectal and Pelvic Floor Diseases, (BL, CW, JZ, MS, XZ, JW, HL); Institute of Human Virology, (BL, CW, JZ, MS, XZ, HL) Key Laboratory of Tropical Disease Control (Ministry of Education); Sun Yat-sen University, Guangzhou (BL, CW, JZ, MS, XZ, HL); Dongguan Health School, Dongguan, China (BL); Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands (JZ, RPK, AGK); and Advanced Clinical Research Center, Institute of Medical Science, University of Tokyo, Tokyo, Japan (AI).
authors.forename: Biyan
authors.initials: B
authors.lastname: Lu
authors.forename: Chenliang
authors.initials: C
authors.lastname: Wang
authors.forename: Junxiao
authors.initials: J
authors.lastname: Zhang
authors.forename: Roland P
authors.initials: RP
authors.lastname: Kuiper
authors.forename: Minmin
authors.initials: M
authors.lastname: Song
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Zhang
authors.forename: Shunxin
authors.initials: S
authors.lastname: Song
authors.forename: Ad Geurts van
authors.initials: AGV
authors.lastname: Kessel
authors.forename: Aikichi
authors.initials: A
authors.lastname: Iwamoto
authors.forename: Jianping
authors.initials: J
authors.lastname: Wang
authors.forename: Huanliang
authors.initials: H
authors.lastname: Liu
mesh_terms: D000199:Actins / Q000378:metabolism; D000328:Adult; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000235:genetics; D014408:Biomarkers, Tumor / Q000378:metabolism*; D003937:Diagnosis, Differential; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism*; D050939:Gene Fusion / Q000235:genetics; D006801:Humans; D058965:MART-1 Antigen / Q000378:metabolism; D058950:Melanoma-Specific Antigens / Q000378:metabolism; D054973:Perivascular Epithelioid Cell Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism*; D058951:gp100 Melanoma Antigen
chemical_list: D000199:Actins; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D014408:Biomarkers, Tumor; D058965:MART-1 Antigen; D058950:Melanoma-Specific Antigens; C548637:PMEL protein, human; C069203:TFE3 protein, human; D058951:gp100 Melanoma Antigen