膀胱原発悪性血管周囲類上皮細胞腫瘍（PEComa）胆嚢転移の1例

The perivascular epithelioid cell family of tumors (PEComas) includes common lesions such as angiomyolipomas, lymphangioleiomyomas, and clear cell sugar tumors of the lung. Less frequently, PEComas arise in various other locations throughout the body, including the soft tissue, bone, and the visceral organs. We report the case of a 64-year-old man who underwent total cystectomy because of a primary malignant PEComa of the bladder in August 2010. The patient was treated with the mammalian target of rapamycin inhibitor for lung and bone metastasis from April 2011 and showed stable disease. Computed tomography showed a growing mass in the neck of the gallbladder 5 months later, which was suspected to be gallbladder cancer. Cholecystectomy and lymphadenectomy was performed in February 2012, and histopathological examination indicated gallbladder metastasis from the primary malignant PEComa of the bladder. This is, to our knowledge, the first report of malignant PEComa metastasis to the gallbladder.