Lepromatous Leprosy Mimicking Sarcoidosis With Elevated Serum ACE Levels: A Deceptive Granulomatous Presentation

Granulomatous diseases often present with overlapping clinical and histopathological features, posing a diagnostic challenge, particularly in regions endemic for tuberculosis. We report the case of a 68-year-old diabetic male with a significant smoking history who presented with progressive shortness of breath and cough for almost three weeks' duration and multiple cutaneous nodules, present for six years, that increased in size and number over two months before presentation. Initial evaluation revealed normal chest imaging, negative microbiological tests for tuberculosis, a non-reactive Mantoux test, and elevated serum angiotensin-converting enzyme (ACE) levels, raising suspicion for the presence of granulomatous disease, like cutaneous tuberculosis, sarcoidosis, and other non-tuberculosis mycobacteria. However, further evaluation, including dermatological assessment and histopathological examination of skin lesions, which demonstrated foamy histiocytic infiltration, was performed. Wade-Fite staining revealed numerous acid-fast bacilli with a high bacterial index, confirming the diagnosis of lepromatous leprosy. The patient was initiated on multidrug therapy with rifampicin, dapsone, and clofazimine, with close follow-up. This case highlights the importance of maintaining a broad differential diagnosis in granulomatous diseases and emphasizes the need for tissue diagnosis before initiating empirical therapy, especially in tuberculosis-endemic settings.