Tuberculous myositis: a rare but existing clinical entity

Objectives. To investigate the clinical characteristics of patients with tuberculous myositis. Methods. From January 1996 to March 2001, patients with positive cultures of Mycobacterium tuberculosis or histology-proven caseous granulomatous inflammation from muscular specimens were identified and their medical records were reviewed. Results. Thirty-five patients were identified. Infection-related myositis was initially suspected in 20 patients (57.1%). The routes of infection were contiguous spread in 22 patients (62.8%), haematogenous spread in 10 (28.6%) and traumatic inoculation in three (8.6%). Five patients (14.3%), including the three who had received corticosteroids, died of uncontrolled sepsis. The computed tomography or the magnetic resonance imaging of the involved muscles showed findings suggestive of tuberculous myositis in 15 patients (42.9%). Conclusions. Tuberculosis should be considered as one of the possible aetiologies of myositis, especially among patients with suggestive radiographic findings or in endemic areas of tuberculosis. Patients who develop tuberculous myositis after using corticosteroids have poor prognoses.