Carcinoma of the gall-bladder arising in adenomyomatosis

We describe a case of well differentiated adenocarcinoma of the gall-bladder that arose from a localized type of adenomyomatosis. Grossly, the cancer was located in the fundus and exhibited a polypoid and well demarcated nodule with multiple small cysts. Histologically, the nodule consisted of glandular structures and stroma containing bundles of smooth muscle cells. The glandular epithelia were varied in appearance, ranging from malignant to benign glands. The adenocarcinoma was limited to the nodule, with normal surface mucosal epithelia and without obvious stromal invasion.