Histiocytic appearance of metastatic lobular breast carcinoma.

Autopsy findings in a case of widely disseminated lobular breast carcinoma showed an unusual histiocytoid appearance in metastases to the uterus and parathyroid gland. This morphology for breast carcinoma has been previously reported in eyelid metastases. Recognition of this pattern in other metastatic sites has important diagnostic and therapeutic implications. Problems might have arisen if the polypoid uterine mass had been the presenting lesion during life. We also review the occurrence of metastatic breast carcinoma in the uterus and parathyroid gland.