Polypoid leiomyosarcoma of the gallbladder: study of a case associated with adenomyomatous hyperplasia.

A case of polypoid leiomyosarcoma of the gallbladder arising in association with pre-existing adenomyomatous hyperplasia is described. The patient, a 34-year-old woman with symptoms of cholelithiasis, underwent a cholecystectomy for gallstones. The resected specimen showed, in addition to multiple stones, a large, rubbery, broad-based polypoid mass in the fundus. Histologic examination showed a malignant spindle cell proliferation with immunophenotypic features of smooth muscle differentiation. The base of the lesion showed features of adenomyomatous hyperplasia. The possible relationships of this lesion with adenomyomatous hyperplasia and other stromal lesions of the gallbladder are reviewed.