Extragastrointestinal stromal tumor and liver transplantation: case report and review.

The occurrence of de novo malignant neoplasias has been shown in postransplant patients under imunosuppression. It is the second leading cause of late death in liver transplant recipients. The greatest incidence is seen in cancers associated with chronic infection by human papilloma virus, skin cancers, oropharyngeal, and gastrointestinal (GI) malignancies. GI stromal tumors (GISTs) are the most common mesenchymal tumors of the GI tract. Rare cases are identified outside the GI tract are collectively known as extragastrointestinal stromal tumors (EGISTs). We present an EGIST case in a liver transplantation patient. A 64-year-old man underwent liver transplantation because of cirrhosis (hepatitis B virus and alcoholism) and hepatocellular carcinoma. Histopathologic findings revealed 2 trabecular hepatocellular carcinomas: a 3.5-cm-diameter lesion located at segment VIII and another 2-cm one at segment V. Seven months later, he noticed a hardened, mobile, painless, 3-cm subcutaneous nodule in the perineum localized in the right lateral quadrant 2 cm distant from the anus. A surgical resection with 1 cm margin yielded a histopathology report of a 5.0 x 3.0 cm spindle cell stromal tumor. The immunohistochemical profile was compatible with a GIST, with 5 mitosis per 50 high-powered fields. This tumor is extremely rare after liver transplantation but has shown a good outcome up to now.