A Rare Case of Idiopathic Granulomatous Mastitis in a Nulliparous Woman with Hyperprolactinemia

Abstract

Idiopathic granulomatous mastitis (IGM) is a rare, benign, and chronic inflammatory condition of the breast. Women of child-bearing age with a recent history of pregnancy and lactation are usually affected, and clinical picture mimics inflammatory breast cancer or breast abscess. The etiology is not well defined but proposed to be a localized immune reaction to the breast tissue. Here, we report a case of a 41-year-old female who presented with left breast pain and discharge and a clinical diagnosis of breast abscess was made. No improvement with antibiotics was noted and she underwent mammography and diagnostic ultrasound of the affected breast. A biopsy of the lesion was obtained which revealed chronic granulomatous inflammation confirming the diagnosis of IGM. She was also found to have hyperprolactinemia secondary to a prolactinoma following which the patient was started on steroid and bromocriptine.

Keywords: hyperprolactinemia; idiopathic granulomatous mastitis; prolactinoma.

Figure 1. Breast ultrasound depicting multiple complicated cystic lesions (yellow and green arrows).

Figure 2. Histopathology showing benign breast tissue with marked acute and chronic inflammation and granulomatous inflammation evident by the presence of noncaseating granuloma (black arrow).

Figure 3. MRI brain in sagittal section showing abnormal enlargement of the pituitary gland (yellow arrow) with extension into the supra-stellar cistern abutting the undersurface of optic chiasm.