Fine-needle aspiration cytology of adenoid cystic carcinoma of the breast.

Adenoid cystic carcinoma (ACC) of the breast is a rare variant of breast malignancy and has a better prognosis than its counterpart in the salivary glands. In this communication, our experience with seven cases of ACC of the breast is presented in which the diagnosis was established on fine-needle aspiration cytology (FNAC). The cytologic samples in all cases were cellular and featured three-dimensional clusters of uniform ductal epithelial cells with cystic spaces, bland nuclei, fine chromatin, and scanty cytoplasm arranged around spheres or cores of homogenous material. The cytodiagnosis of ACC in all cases correlated with subsequent examination of cell blocks of the aspirate and tissue. The cytodiagnostic criteria for ACC of the breast which are useful in a correct FNAC diagnosis are discussed.