Tuberculous arthritis is an uncommon form of musculoskeletal tuberculosis characterized by an indolent clinical course that frequently leads to delayed diagnosis and advanced joint destruction. We report the case of a 69-year-old male with poorly controlled type 2 diabetes mellitus complicated by retinopathy and nephropathy, who presented with progressive right shoulder pain. Magnetic resonance imaging demonstrated erosive inflammatory changes in the glenohumeral joint and incidentally revealed a cavitary lesion in the right upper lobe, highly suggestive of pulmonary tuberculosis. Subsequent clinical reassessment uncovered a history of chronic left hip pain preceding the shoulder symptoms. Imaging of the hip demonstrated advanced joint destruction. Histopathological and microbiological analyses confirmed Mycobacterium tuberculosis infection. This case highlights the importance of integrating imaging findings with clinical history and emphasizes how careful evaluation beyond the primary field of view may provide critical diagnostic clues. Tuberculosis should be considered in the differential diagnosis of chronic destructive arthritis, particularly in immunocompromised patients.