Breast and cutaneous mycobacteriosis: diagnosis by fine-needle aspiration biopsy.

The breast and skin are considered to be rare sites of extrapulmonary mycobacterial infection, comprising 0.1% to 0.5% of all tuberculosis cases, respectively. Fine-needle aspiration biopsy (FNAB) is a rapid and minimally invasive approach to diagnose extrapulmonary tuberculosis, and has been used successfully in identifying tuberculous lesions in the lymph nodes, thyroid, kidney, pancreas, vertebrae, and testis. Two cases of extrapulmonary mycobacteriosis diagnosed by FNAB are described: a 59-year-old Hispanic male with cutaneous mycobacterial infection of the head and neck region, and a 58-year-old white male with a unilateral tuberculous mastitis. In both instances, the FNAB material demonstrated acute neutrophilic exudate, few isolated aggregates of epithelioid histiocytes and lymphocytes, and on Fite-Farraco stain mycobacteria. Reported cases of tuberculosis diagnosed by FNAB have been few; this is the first case of cutaneous tuberculosis diagnosed by FNAB.