title: Microglandular adenosis of the breast. A clinicopathologic study of 11 cases with ultrastructural observations.
abstract: The clinical and pathologic features of 11 examples of microglandular adenosis of the breast are presented. Microglandular adenosis is a rare, benign lesion that is easily confused with carcinoma. It is characterized by a concentrated proliferation of round glands with open lumens in a densely homogeneous stroma that clearly delineates microglandular adenosis from the adjacent uninvolved breast. The glands are lined by a single layer of cells with distinctly vacuolated or granular cytoplasm. Ultrastructurally, the single layer of epithelial cells lacks cytoplasmic protrusions and is surrounded by a thick multilayered basement membrane. Light- and electron-microscopic features that help distinguish microglandular adenosis from well-differentiated (tubular) carcinoma and sclerosing adenosis, entities with which it is easily confused, are discussed.
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis; D000328:Adult; D000368:Aged; D001940:Breast / Q000648:ultrastructure; D001943:Breast Neoplasms / Q000175:diagnosis; D003937:Diagnosis, Differential; D005260:Female; D005348:Fibrocystic Breast Disease / Q000175:diagnosis / Q000648:ultrastructure*; D006801:Humans; D008875:Middle Aged