Pleural Effusion Revealing Visceral Leishmaniasis: A Diagnostic Pitfall in an Immunocompetent Patient

Pleural involvement in visceral leishmaniasis (VL) is rare and may pose a diagnostic challenge, particularly when it mimics pleural tuberculosis. We report the case of a 39-year-old immunocompetent man who presented with a dry cough and night sweats. Initial workup revealed a small lymphocytic exudative pleural effusion, and pleural biopsy showed granulomatous inflammation with a tuberculoid appearance, leading to empirical antituberculosis treatment. Because of clinical deterioration, persistent pleural effusion, and negative molecular testing for Mycobacterium tuberculosis, further investigations were performed. Thoracoabdominal computed tomography demonstrated a moderately sized loculated right pleural effusion without hepatosplenomegaly. Thoracoscopic pleural biopsy revealed intracellular structures compatible with leishmaniasis, and review of the previous specimen confirmed intracytoplasmic Leishman-Donovan bodies within histiocytes. Serology for Leishmania was strongly positive, and treatment with liposomal amphotericin B led to a favorable clinical evolution, although residual pleural thickening persisted. This case underscores the need to consider VL in the differential diagnosis of persistent lymphocytic exudative pleural effusion, even in immunocompetent patients.