Invasive mammary carcinoma with osteoclast-like giant cells diagnosed by fine-needle aspiration biopsy: review of the cytologic literature and distinction from other mammary lesions containing giant cells.

Invasive carcinoma with osteoclast-like giant cells is an unusual type of mammary adenocarcinoma with few cases reported in the cytology literature. We present the cytologic findings in a case of invasive cribriform carcinoma of the breast containing osteoclast-like giant cells diagnosed by fine-needle aspiration biopsy. The smears displayed three-dimensional cohesive cluster cells of uniform epithelial cells admixed with numerous multinucleated giant cells that morphologically resembled osteoclasts. Core biopsy confirmed the cytologic diagnosis. Immunohistochemical studies indicated that the multinucleated giant cells were of histocytic origin. Knowledge of the bland cytologic pattern and the admixture of giant cells seen in invasive cribriform carcinoma with osteoclast-like giant cells should avoid making a false negative diagnosis on aspiration biopsy. Copyright 2004 Wiley-Liss, Inc.