Tuberculous dactylitis pseudotumor of an adult thumb: a case report.

Tuberculous dactylitis is an uncommon condition which is particularly difficult to differentiate from other lesions, particularly tumors. We report the case of a 56-year-old, healthy, left-handed person who consulted for progressive painful swelling of 8-month duration in the right thumb, which had developed after direct trauma. The plain radiograph of the thumb revealed extensive destruction of the proximal phalanx associated with pathological fracture. Magnetic resonance imaging (MRI) showed replacement of the affected phalanx with prominent soft tissue mass with extension outside the bone margins. The diagnosis of tuberculous dactylitis was based on histological characteristics and positive acid fast bacilli using Ziehl-Neelsen stain. Surgical debridement and anti-tuberculous chemotherapy eradicated the infection. Seven years post treatment, the patient had good function of the thumb with no significant disability interfering with his daily activity.