International Journal of Morphology
On-line version ISSN 0717-9502
FONSECA, Ismael Bernardo et al. Extra-gastrointestinal Stromal Tumors (EGISTs): Review of Four Cases with Immunohistochemical Analysis. Int. J. Morphol. [online]. 2010, vol.28, n.4, pp. 991-998. ISSN 0717-9502. doi: 10.4067/S0717-95022010000400002.
Gastrointestinal stromal tumors or GISTs are neoplasms belonging to the soft tissue sarcomas and can be located anywhere in the body. They most frequently occur in the gastrointestinal tract (esophagus to rectum), in fact, over 50% occur at the gastric level. However, they have also been described elsewhere (mesentery and omentum, retroperitoneum, gall bladder, bladder wall and uterus). Extragastrointestinal latter location have been published by the acronym EGIST (representing 5% of all GISTs. We report four cases of EGIST (2 of mesenteric and retroperitoneal location) describe the histopathological, clinical aspects and immunohistochemical profile. We studied 32 cases of GISTs in a prospective and retrospective analysis of files for the Service and IInd Chair of Pathology (Emergency Municipal Hospital), Hospital Córdoba, and Our Lady of Mercy, Cordoba (Argentina), between 1987 and 2008. In that series were extracted and analyzed four cases (two retroperitoneal and two mesenteric). All cases were female patients whose ages ranged from 42 to 72 years who consulted for abdominal pain, pelvic pain and weight loss. Tumor size ranged from 4 to 28 cm. All were partially cystic mass, showing hemorrhage and necrosis, in varying degrees. Microscopic patterns were observed 2 spindle and epithelioid-looking lax, arranged in bundles intertwined with low mitotic index. Immunohistochemistry panel: Vimentin, CD34 and CD117: Positive. Actin, chromogranin and S-100: Negative. Ki 67: + 2 to 10%. Diagnosis: extragastrointestinal stromal tumor, borderline. Complete histopathological and immunohistochemical panels should be considered for a definite diagnosis. The main peculiarity of the present cases is their location. The EGIST are rare (5% of GIST).
Keywords : GIST; c-Kit; Extragastrointestinal stromal tumors; Interstitial cells of Cajal; Retroperitoneum; Mesentery; Borderline.