Articular flare-up of systemic scleroderma revealing a rare form of tuberculosis of the shoulder and extensor tendons: a case report and literature review.

Tuberculosis remains a major public health concern, particularly in countries where it is still endemic. Tuberculous bursitis and tenosynovitis are rare extrapulmonary manifestations, and their association with systemic autoimmune diseases such as scleroderma is seldom reported in the literature. We report the case of a 61-year-old patient with systemic scleroderma, complicated by diffuse interstitial lung disease and treated with mycophenolate mofetil, who developed tuberculous shoulder bursitis and wrist extensor tenosynovitis. The microbiological diagnosis was confirmed by ultrasound-guided aspiration of the subacromial-subdeltoid bursa, revealing the presence of Mycobacterium tuberculosis, detected by Ziehl-Neelsen staining, GeneXpert PCR and culture. Histological analysis of synovial tissue fragments demonstrated epithelioid granulomas with caseous necrosis, confirming the tuberculous origin.