A Rare Convergence: Adult-Onset Langerhans Cell Histiocytosis and HIV Infection.

While primarily described in children, adult-onset Langerhans cell histiocytosis (LCH) has been reported, albeit infrequently. In the present scenario, we unveil a unique case of adult-onset LCH in an HIV-infected individual. After the diagnosis was made, the patient was successfully treated and demonstrated total disease remission. This case illustrates the diagnostic challenge that rare clinical entities such as LCH pose, especially in the context of an untreated HIV infection. Furthermore, the complexity of treating adult-onset Langerhans cell histiocytosis in an HIV-positive patient is highlighted, with emphasis given on a multidisciplinary approach. LEARNING POINTS: Novelty: the case study provides knowledge on the uncommon occurrence of LCH in adults, especially within the setting of untreated HIV infection, underlining the significance of prompt detection and medical treatment.Diagnostic challenges: The scenario depicts the difficulty in diagnosing LCH in the presence of HIV, necessitating an array of diagnostic procedures.Multidisciplinary approach: This case's effective management emphasises the crucial role of a multidisciplinary approach when dealing with complex medical conditions.