Aspiration biopsy cytology of secretory carcinoma of the breast.

Aspirate from a secretory carcinoma of the breast showed malignant epithelial cells present singly or in large sheets with strong cellular cohesiveness. Tumor cells displayed ill-defined, granular, or vacuolated cytoplasm. Intracytoplasmic globular material was periodic acid-Schiff positive and resistant to prior diastase digestion. The cytologic differential diagnosis with other breast cancers is briefly discussed.