Microglandular adenosis is a very uncommon benign proliferative disorder of the breast that may mimic tubular carcinoma radiologically and pathologically. We describe the radiological features of this rare condition in a patient with BRCA 1 mutation. To our knowledge, this is the first case of microglandular adenosis reported in the radiology literature. The relationship between microglandular adenosis and malignancy and the association between BRCA 1 and proliferative benign disorders are also discussed.