Disseminated Mycobacterium haemophilum causing granulomatous mastitis

We present the case of a 58-year-old female with celiac disease, obesity, and recently diagnosed type 2 diabetes mellitus who developed a rash on her left thigh which spread and progressed to her arms, face, and abdomen. A biopsy of the left forearm grew <i>Mycobacterium haemophilum</i>. Weeks after the diagnosis of the <i>M. haemophilum</i> skin infection, the patient underwent a screening mammogram which showed new masses in both breasts. A biopsy of a left breast mass revealed cystic granulomatous inflammation with scattered neutrophils and lymphocytes within fibroadipose tissue. PCR and sequencing from breast tissue and AFB culture confirmed <i>M. haemophilum</i>. The patient was also later diagnosed with sinonasal involvement. No underlying immunodeficiency has been identified. This case highlights dissemination of <i>M. haemophilum</i> to multiple sites including skin, breast, and sinonasal tissues in a diabetic patient who was not otherwise immunocompromised. To our knowledge, it is the first reported case of granulomatous mastitis caused by <i>M. haemophilum</i>.