Clinicopathologic Analysis of 4 Perivascular Epithelioid Cell Tumors (PEComas) of the Gastrointestinal Tract
ABSTRACT This study describes the clinical, histologic, and immunohistochemical features of four cases of GI PEComa. The size of the tumors ranged from 3.5 to 6.0cm in diameter, and all were located in wall of the large bowel. Microscopically, the tumors were characterized by an epithelioid arrangement of tumor cells, which had abundant clear to pale eosinophilic granular cytoplasm, vesicular nuclei and prominent nucleoli. The stroma was rich in capillaries, a sinusoidal vasculature and thick-walled blood vessels. Mitotic figures were generally rare. Immunohistochemically, the tumors were positive for Vimentin (4/4), HMB-45 (4/4), Melan-A(4/4),alpha-smooth muscle actin (4/4), and desmin (3/4). The patients have been well with no evidence of disease at 8, 15, 32 and 36 months,respectively, after the surgical operation. GI tract PEComas should be regarded as tumors of an uncertain malignant potential until long-term outcome data for a larger number of patients become available.
SourceAvailable from: Munetaka Masuda[Show abstract] [Hide abstract]
ABSTRACT: We report a case of perivascular epithelioid cell tumor arising in the rectum of a 55-year-old woman. The tumor was treated by transanal endoscopic microsurgery. After 1 year follow-up, the patient is alive with no radiologic or endoscopic evidence of recurrence. Perivascular epithelioid cell tumor is a rare mesenchymal tumor characterized by co-expression of melanocytic and smooth muscle markers. This rare tumor can arise in various organs, including the falciform ligament, uterus, uterine cervix, liver, kidney, lung, breast, cardiac septum, pancreas, prostate, thigh, and gastrointestinal tract. Perivascular epithelioid cell tumor of the gastrointestinal tract is very rare, with only 23 previously reported cases. We review the literature on perivascular epithelioid cell tumors arising in the gastrointestinal tract.World Journal of Surgical Oncology 01/2014; 12(1):12. DOI:10.1186/1477-7819-12-12 · 1.20 Impact Factor
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ABSTRACT: Glomus tumor (GT) of the stomach is a rare mesenchymal tumor. There have been few detailed studies on these tumors. A total of 1894 cases of resected gastric mesenchymal tumors were collected and eleven confirmed gastric GTs were studied. The clinical, pathological, immunohistochemical, ultrastructural and molecular characteristics of the tumors were analyzed through a retrospective study. Histologically, most tumors had gastric smooth muscle immediately adjacent and surrounding the tumor. Tumor cells around blood vessels were small, uniform, and round. Foci of hyaline and myxoid changes were observed. Prominent clear cell features were observed in two tumors. Positive expression of α-smooth muscle actin (α-SMA), laminin, collagen type IV, and vimentin was detected by immunohistochemical analysis in all patients. However, in clear cell areas the expression of α-SMA, laminin, and type IV collagen were mild, while Syn was positive. Moreover, myofibrils and neuroendocrine granules were also present in the cytoplasm of these cells. No C-kit or PDGFR-α genetic mutations were detected in all patients. To conclude, Our results show that GTs in the stomach are histologically and immunophenotypically fully comparable with the glomus tumors of peripheral soft tissues. Neuroendocrine granules and neuroendocrine differentiation were identified in some of the gastric GT cells. Thus, a novel subtype of gastric glomus tumor expressing neuroendocrine cell markers may exist.International journal of clinical and experimental pathology 01/2014; 7(4):1438-48. · 1.78 Impact Factor
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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 casesMicroscopically, 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.Medicine 01/2015; 94(3):e393. DOI:10.1097/MD.0000000000000393 · 4.87 Impact Factor