ABSTRACT

Adenoid cystic carcinoma (ACC) most commonly occurs in the major and minor salivary glands of the head and neck, but it also has been described in the breast, upper respiratory tract, esophagus, uterine cervix, lacrimal glands, etc. Adenoid cystic carcinoma is composed of two types of cells: small cells with dark nuclei and scanty cytoplasm and larger cells with vesicular nuclei and vacuolated cytoplasm. The glands are lined by an inner layer of small dark secretory cells and an outer layer of myoepithelial cells. The large cystic spaces are bordered by myoepithelial cells and contain a pale, homogenous material. Immunoperoxidase staining for prostate-specific acid phosphatase (PSAP) and prostate-specific antigen (PSA) is negative in the tumor. Recently, glandular lobules and ducts histologically identical to salivary gland tissue were described in the prostate. True mucinous adenocarcinoma must be differentiated from primary and secondary mucinproducing carcinomas of the gland.