Mycobacterium avium complex infection in a neck abscess: a diagnostic pitfall in fine-needle aspiration biopsy of head and neck lesions.

Fine-needle aspiration biopsy (FNAB) is a useful tool in the diagnosis of mycobacterial disease, especially Mycobacterium tuberculosis. However, nontuberculous mycobacterial infection diagnosed with FNAB material is much rarer, with Mycobacterium avium complex being the most common. In this report, we present the case of a 21-year-old HIV positive man, who presented with a unilateral, tender, enlarging cervical neck mass. FNAB had revealed acute inflammation. Mycobacterium avium complex grew in culture from the material that was aspirated and was confirmed by DNA probe. Because of the paucity of articles on this subject in the cytology literature, it is important to reiterate the value of the material aspirated at the bedside and the clinic in the diagnosis of infectious disease. When faced with antibiotic-resistant cellulitis and abscesses, the FNAB material must be sent for acid fast bacteria smears and culture.