18F-FDG PET/CT Incidental Finding of Rare Extrapulmonary Presentation of Mycobacterium tuberculosis.

A 41-year-old woman presented with a left breast mass for which mammography was performed. Mammogram revealed a suspicious BI-RADS 4, palpable left breast mass with associated nipple retraction. As malignancy was suspected, the patient underwent breast MRI and 18F-FDG PET/CT for staging. Multiple ultrasound guided biopsies were then performed of the left breast, left axillary lymph nodes, and left cervical lymph nodes. Final pathology was negative for malignancy, but final cultures grew Mycobacterium tuberculosis (Tb). The patient was initially intolerant to frontline medications, but eventually successfully treated with isoniazid, ethambutol, pyrazinamide, and moxifloxacin, as demonstrated by posttreatment mammography.