Fine-Needle Aspiration Cytopathology-An Accurate Diagnostic Modality in Mammary Carcinoma With Osteoclast-Like Giant Cells

BACKGROUND: Invasive ductal carcinoma with osteoclast-like giant cells (OGCs) is a very rare breast tumor the main characteristic of which is the presence of multinucleated cells of histiocytic nature. METHODS: The authors report a study of 8 consecutive cases of fine-needle aspiration cytopathology (FNAC) of breast nodules in which OGCs and malignant epithelial cells were associated and diagnosed as mammary carcinoma with OGCs. These cases were selected over a period of 5 years from more than 6000 patients who were examined during a weekly, single-day, multidisciplinary breast clinic. The corresponding biopsies and surgical specimens were examined histologically in an immunohistochemical study using a histiocytic marker (cluster of differentiation 68 [CD68]). RESULTS: Conventional histologic analysis made it possible to diagnose 5 of the 8 cases as mammary carcinoma with OGCs; whereas, in the other 3 cases, OGCs were not detected without the help of immunohistochemistry. CONCLUSIONS: FNAC appeared to be a very efficient way to diagnose breast carcinoma with OGCs, because it detected forms with only a few OGCs that usually are not observed at histologic diagnosis. Consequently, the current results indicated that mammary carcinoma with OGCs may be more frequent than reported previously. Cancer (Cancer Cytopathol) 2010; 118: 468-73. (C) 2010 American Cancer Society.