Granulomatous Lobular Mastitis Following Drug-Induced Galactorrhea and Blunt Trauma

We report a single case of chronic granulomatous lobular mastitis following metoclopramide-related galactorrhea and a blunt trauma in a young parous woman who underwent two conservative operations before becoming symptom-free. We have found only two other literature cases associated with hyperprolactinemia, and our case could be another of this etiologic group. The absence of well-formed granulomas in the first histology specimen in the present case was misleading; it was reinterpreted as granulomatous mastitis only after the second specimen was examined. Reinterpretation was based on the lobular distribution of a lymphoplasmocytic infiltrate (nonspecific chronic lobulitis) and the presence of epithelioid cell sheets and neutrophils in the absence of well-formed granulomas. The case lends further support to the theory of a local immune response initiated by the secreted material or by one of its components in the formation of granulomas. However, contributory factors such as the trauma in this case (a blow from a shovel handle) or systemic disease in others may play a role in the development of the disease, which in some instances may represent a pattern of tissue reactions to different noxious agents.