Breast carcinoma with osteoclast-like giant cells: morphological and ultrastructural studies of a case with review of the literature

Primary carcinoma with osteoclast-like giant cells is a very rare tumour of the female breast. The clinical course, histological, immunohistochemical and ultrastructural features of 61 cases of invasive duct carcinoma with os teoclast-like multinucleated giant cells (OMGCs) are reviewed and a new cas e is presented. The median patient age of ail patients included in the revi ew was 42 years, the tumour was located in the upper outer quadrant and the mammographic and gross findings were of a well-defined tumour of dark-brow n colour, resembling a metastatic melanoma. Follow-up data in the literatur e have shown that 86% of patients with these tumours are still alive after 5 years. Histologically, these tumours are invasive ductal carcinomas with OMGCs nex t to the neoplastic glands and within their lumen. Signs of recent and past haemorrhage are ubiquitously present in the highly vascularized stroma. Im munohistochemical and ultrastructural studies have claimed a benign histioc ytic nature of the OMGCs; they may represent a special type of polykaryon, distinct from both osteoclasts and inflammatory giant cells. (C) 2001 Harco urt Publishers Ltd.