Sporadic exophytic hepatic angiomyolipoma.

Angiomyolipomas are rare mesenchymal tumours consisting of smooth muscle, blood vessels and adipocytes in variable proportions. These tumours are more usually seen in kidneys (incidence 0.3-3%), and the extrarenal location is rare. Since its initial description by Ishak in 1976, only about 200 cases of hepatic angiomyolipomas have been reported. We describe the case of a 59-year-old woman, without tuberous sclerosis, with a 6 cm tumour in hepatic segments II and III, gallbladder with parietal calcification and lithiasis. She was proposed to bisegmentectomy (II and III) and cholecystectomy, which were performed without complications. The pathological examination confirmed the diagnosis of hepatic angiomyolipoma (positive for HMB45 and focally positive for HHF35) and chronic cholecystitis. Although typically benign, the emergence of cases with malignant behaviour--recurrence or distant metastasis--led to a change in attitude towards these lesions, from clinical surveillance to surgical excision, with few exceptions.