Disseminated granulomatous disease: TB or sarcoidosis – a diagnostic and therapeutic challenge

The overlapping clinical presentation of tuberculosis (TB) and sarcoidosis presents a significant diagnostic and therapeutic challenge, particularly in TB-endemic regions. This case study reports a 52-year-old female presenting with disseminated granulomatous disease affecting the lungs, lymph nodes, skin, and bone, raising concerns for both TB and sarcoidosis. The diagnostic evaluation included serum angiotensin-converting enzyme (ACE) levels, bronchoalveolar lavage (BAL), whole-body PET-CT, histopathological examination, and CBNAAT testing. Results revealed non-caseating granulomas without evidence of Mycobacterium tuberculosis. Despite the absence of microbiological confirmation for TB, the presence of osteolytic bone lesions further complicated the differential diagnosis. In light of the diagnostic uncertainty, the patient initially received empirical antifungal therapy, followed by a corticosteroid trial, which led to partial clinical improvement. However, the persistence of fever and systemic symptoms prompted the initiation of anti-tubercular therapy (ATT). A marked response to the combination of corticosteroids and ATT supported the possibility of an overlap syndrome, namely tuberculous sarcoidosis. This case highlights the intricate interplay between TB and sarcoidosis and underscores the value of multimodal diagnostic strategies and a stepwise therapeutic approach in endemic settings. It also emphasizes the importance of long-term follow-up to monitor treatment response and assess the risk of relapse or corticosteroid dependence.