Tuberculous extensor tenosynovitis of the wrist in a patient with systemic lupus erythematosus mimicking a giant cell tumour: A case report and review of literature

Introduction & importance: Extrapulmonary tuberculous involvement of the musculoskeletal system is not common and seen in less than 10 % of all cases. The bidirectional association between tuberculous infection of the musculoskeletal system and rheumatological diseases has been widely recognized and arises both as a result their underlying immunosuppressive state and of drug induced immunosuppression. Case presentation: A 45-year-old female on treatment for SLE, in remission, presented with a slow growing mass over the dorsum of the right wrist with functional impairment which was clinically and radiologically compatible with a giant cell tumour. Pathological examination after surgical excision revealed pathognomonic features of tuberculous tenosynovitis. Multidrug antituberculous therapy was commenced. Clinical discussion: Clinical diagnosis of tuberculous tenosynovitis is difficult due to the non-specific clinical symptoms and signs. Laboratory investigations are usually normal except for ESR which may be elevated. Delay in establishing therapy may lead to dissemination of mycobacteria to the surrounding bursae, muscles and soft tissue leading to joint and tendon damage. Detection of mycobacteria through TB culture and microscopy of the specimen has a low sensitivity and therefore treatment should be promptly initiated when typical pathological findings are seen. Conclusion: Tuberculous tenosynovitis of the extensor tendons is a rare clinical presentation and must be suspected in cases of chronic and recurrent tendon sheath infection especially in an immunocompromised patient in a TB endemic country. The lack of clinical suspicion, nonspecific findings and mimicry of other conditions can lead to delayed diagnosis and complications.