After extraction of a tooth a 12-year-old girl developed infiltration in the submandibular region which despite ATB treatment increased in size. Examination by magnetic resonance revealed an expansive tumourous focus along the ramus mandibulae of obscure etiology along with pathologically enlarged regional nodes. Therefore peroperatively a histological examination was made with subsequent extirpation of the submandibular node. Cultivation revealed infection caused by Mycobycterium chelonae, and based on sensitivity test to antibacterial drugs, the girl was successfully treated by a triple combination of antibiotics.

        Key words: peripheral lymphadenitis, Mycobacterium chelonae