Perivascular Epithelioid Cell Tumor of Gastrointestinal Tract

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.

A systematic review

“…[ 10 ] Thirty two women and 18 men were recorded in the literatures so that it is believed to have women predomination. The most frequently involved location is colon (N = 20), [ 11 – 26 ] followed by mesentery (N = 10), [ 27 – 33 ] stomach (N = 4), [ 34 – 37 ] duodenum (N = 4), [ 38 – 41 ] ileum (N = 4), [ 4 , 42 , 43 ] cecum (N = 3), [ 12 , 44 , 45 ] oral cavity (N = 1), [ 46 ] esophagus (N = 1), [ 47 ] jejunum (N = 1), [ 48 ] ileocecal junction (N = 1) [ 49 ] and one case without exact site of origin (N = 1, multiple parts of GI involved). [ 9 ] Refined to GI PEComas-NOS of colon, rectum (N = 7) seems to be the most common involved region.…”

“…Perivascular epithelioid cell tumors of gastrointestinal tract (GI PEComas-NOS) takes a proportion of about 20% to 25% of PEComas-NOS. [ 4 ] There are 50 cases of GI PEComas-NOS recorded in the English literature approximately and most of them are case report or small-scale case series research. For the rarity of such a distinctive neoplasm, the epidemiology, clinical presentation, optimal management, and prognosis of it are still unascertainable.…”

Perivascular epithelioid cell tumor of the descending colon mimicking a gastrointestinal stromal tumor: a case report

“…These phenotypes were thought to be compatible with the initial diagnosis of GISTs with a PDGFRα mutation [3, 9]. However, GISTs with a PDGFRα mutation most commonly arise in the stomach [9, 10], and the tumor is typically DOG1-positive [11, 12]. In contrast to the case of GISTs, PDGFRα positivity and mutations in PDGFRα genes have not been reported in PEComas, to the best of our knowledge.…”

Diagnosis and treatment of malignant PEComa tumours

“…Many anatomical locations have been described for PEComas. In a large analysis 24 pancreatic PEComa cases were presented, of which half were localised in the head of the pancreas [12] and numerous PEComas of the digestive tract [11,15], including the stomach [16], the ileus [17] and the colon [18]. Moreover, single cases in various locations have been described: the greater omentum [19], the gall bladder [20], the common bile duct [21], the breast [22], the thigh bone [6], rib [23], skull base [24], heart [25], pericardium [26], the prostate [27,28], ovary [29], nasal cavity [30], throat [31], eye socket [10], urinary bladder [32], lung [33], and the groin [34].…”