Idiopathic Granulomatous Lobular Mastitis in a Male Breast: A Case Report

Idiopathic granulomatous lobular mastitis (IGLM) that mimics breast cancer both clinically and radiologically is a chronic inflammatory condition of the breast without a known etiology. It usually affects childbearing women and is associated with pregnancy, lactation, or use of oral contraceptives. IGLM in a male breast is extremely rare, and only two case reports have been published. A 60-year-old man was referred to our hospital for right breast mass. He had right breast pain with a small palpable lump for 2 weeks. Ultrasonography (US) was performed with color Doppler US and US elastography. The lesion was diagnosed as IGLM pathologically by 14 gauge core needle biopsy. We describe a very rare case of IGLM arising from a male breast based on ultrasonographic and pathologic findings. IGLM should be considered as a differential diagnosis in male breast diseases, although the imaging findings may not be comparable with typical IGLM.