Co-occurrence of disseminated Mycobacterium kansasii infection and Kikuchi-Fujimoto disease in an immunocompetent patient

Disseminated Mycobacterium kansasii infection and Kikuchi-Fujimoto disease (KFD) are rare and diagnostically challenging conditions, especially when they occur together. They present with similar symptoms such as lymphadenopathy, prolonged fever and weight loss, which often lead to misdiagnoses. This case report describes the uncommon co-occurrence of disseminated M. kansasii infection and KFD in a young female patient who experienced a prolonged, intermittent high-grade fever, weight loss and lymphadenopathy. A lymph node biopsy showed features typical of KFD, while mycobacterial culture detected M. kansasii. She responded well to tailored non-tuberculous mycobacterial therapy, with clinical and radiological improvement. This case underscores the need to consider concurrent infections in patients presenting with KFD-like symptoms. It also contributes to the small body of literature on the co-occurrence of these two conditions.