Perivascular epithelioid cell tumor (PEComa) and Gastrointestinal

AIMS: Gastrointestinal stromal tumour (GIST) may share morphological and/or immunohistochemical features with various intra-abdominal neoplasms, including endometrial stromal sarcoma, perivascular epithelioid cell tumour (PEComa), melanoma and synovial sarcoma. Each of these various neoplasms has characteristic immunohistochemical markers, including epithelial membrane antigen (EMA), CD10, oestrogen receptor alpha (ERa) and/or HMB45, and therefore the primary aim of this study was to determine whether these markers are also expressed by GISTs...

We advance the hypothesis that the telocyte might be the cell of origin of both PEComas (perivascular epithelioid cell tumours) and GISTs (gastro-intestinal and extra-gastrointestinal stromal tumours). The hypothesis is supported by data from the literature reporting that both PEComas and GISTs, as well as telocytes, share the expression of several markers. These data were supplemented by original immunohistochemical tests on selected series. Specifically: (1) Melanoma markers (Melan A, MiTF) typical of PEComas are expressed by a substantial fraction of GISTs...

OBJECTIVE: To study the clinicopathologic characteristics of perivascular epithelioid cell tumor (PEComa), not otherwise specified (NOS) and to evaluate the diagnostic criteria for malignancy. METHODS: The clinical and pathologic features of 31 cases of PEComa-NOS were reviewed. The follow-up data available were analyzed. RESULTS: There were a total of 24 females and 7 males. The age of the patients ranged from 13 to 66 years (mean = 40 years)...

This review examines the histopathologic, immunohistochemical, ultrastructural, and molecular biologic features of epithelioid angiomyolipoma (EAML), with an emphasis on the differential diagnosis of intra-abdominal EAML. Epithelioid angiomyolipoma is an uncommon mesenchymal tumor with malignant potential, frequently associated with tuberous sclerosis complex. Histologically, EAML is characterized by sheets or nests of large polygonal epithelioid cells with abundant eosinophilic or occasionally clear cytoplasm, often with prominent nucleoli, and EAML may include multinucleated and markedly pleomorphic forms...

Perivascular epithelioid cell neoplasms (PEComas) include the common renal angiomyolipoma, pulmonary clear cell sugar tumor, lymphangioleiomyomatosis, and less common neoplasms of soft tissue, gynecologic, and gastrointestinal tracts. Recently, aberrant immunoreactivity for TFE3 protein (a sensitive and specific marker of neoplasms harboring TFE3 gene fusions) has been reported in as many as 100% of PEComas; however, TFE3 gene status in these neoplasms has not been systematically investigated. We used a fluorescence in situ hybridization (FISH) break-apart assay to evaluate for evidence of TFE3 gene fusions in archival material from 29 PEComas...

Perivascular epithelioid cell tumor (PEComa) is a rare mesenchymal tumor. Perivascular epithelioid cell tumors of the gastrointestinal tract are very rare, with only about 20 previous reported cases. We present a 5.5-year-old boy with PEComa of the right colon. Treatment consisted of tumor resection only, without additional adjuvant therapy. Two years after surgery, he remains free of tumor. To the best of our knowledge, this is the youngest reported child with PEComa of the colon. We review the literature concerning PEComas in children, especially those of the gastrointestinal tract...

The connection between angiomyolipoma (AML) of the kidney, clear cell sugar tumor (CCST) of the lung, and pulmonary lymphangioleiomyoma (LAM), was progressively discovered because of the histologic and immunophenotypic similarities between the three tumors and their frequent association with tuberous sclerosis complex (TSC). Morphologically, analogous lesions found in other locations are composed of the unifying cell, the perivascular epithelioid cell (PEC). PEC tumors (or PEComas), other than AML, CCST, and LAM, are not associated with TSC and typically occur in middle-aged adult females...

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...

PEComa of the gastrointestinal tract, composed of perivascular epithelioid cells with myomelanocytic differentiation, is rare with previous literature limited to 16 case reports. There is a marked female preponderance and approximately one-third of the cases occur in the pediatric age group. We report PEComa with lymph node involvement occurring in the rectum of a 15-year-old girl, treated by surgical resection and adjuvant chemotherapy. The patient is well at 9 months follow-up with neither radiologic nor endoscopic evidence of recurrence...

Approximately 10% of patients with gastrointestinal stromal tumors (GIST) develop other neoplasms, either synchronously or metachronously. In this report we describe coexistence of a gastrointestinal stromal tumor and a hepatic perivascular epithelioid cell tumor (PEComa) in a 51-year-old woman with no evidence of tuberous sclerosis. A subcapsular hepatic nodule (0.8 cm in diameter) was found during surgery for symptomatic gastric neoplasm (15 cm in diameter) arising from the lesser curvature. Both tumors revealed histomorphological and immunohistochemical features confirming a diagnosis of a small incidental hepatic PEComa and a high risky extramural gastric GIST, respectively...

Neoplasms of the perivascular epithelioid cell (PEComas) represent a recently described heterogeneous group of mesenchymal tumors characterized by the presence of specific histological, immunohistochemical, and ultrastructural findings. The PEComas encompass a family of neoplasms that include angiomyolipomas, clear cell sugar tumors, and lymphangioleiomyomatosis. The PEComas demonstrate a wide spectrum of clinicobiological behavior and imaging findings. Perivascular epithelioid cell, as the name implies, is a unique cell that is characterized by perivascular distribution and epithelioid morphology...

Epithelioid angiomyolipoma (AML) is the prototype of a heterogeneous group of lesions characterized by the presence of HMB-45 positive cells with clear cytoplasm, perivascular distribution, and combined myomelanocytic features, so-called perivascular epithelioid cells (PECs). These lesions are being increasingly referred to as PEComas. PEComas have been reported at diverse anatomic sites, but mainly in the abdominopelvic cavity and rarely in parenchymatous organs, skin, and soft tissues. Gastrointestinal (GI) PEComas are exceptionally rare, with less than 10 cases documented so far...

The perivascular epithelioid clear cell tumor (PEComa) has been described in a number of locations, including the pancreas, uterus, bladder, prostate, and gastrointestinal tract. We report the existence of a similar tumor occurring in the distal common bile duct of a 51-year-old man admitted for obstructive jaundice. The tumor had characteristic histologic features of a PEComa, including a richly vascular organoid architecture, tumor cells with clear to lightly eosinophilic cytoplasm, and variably prominent nucleoli...