Rare abdominal metastases from occult lobular breast cancer: report of two cases.

Intra-abdominal metastases from breast carcinomas are rarely reported in the literature. Least are those originating from occult breast primary. We report, one case of pancreatic metastasis and one case of metastatic infiltration of the colonic wall, both by occult lobular breast carcinoma. The first patient underwent pancreaticoduodenectomy for obstructive jaundice, with unexpected histological finding of infiltration of distal bile duct, pancreatic gland, portal vein and retroperitoneal soft tissue by lobular carcinoma of the breast. The second patient complained of diffuse abdominal pain associated with constipation and rectal bleeding and underwent endoscopic biopsy of three intestinal strictures, revealing metastatic lobular carcinoma with signet-ring cell morphology. In both cases, a subsequent complete diagnostic work-up demonstrated asymptomatic multiple breast nodules, diagnosed as lobular carcinoma by fine needle aspiration cytology.