A Rare Manifestation of Mycobacterium kansasii as a Cutaneous Infection: A Case Report.

Nontuberculous mycobacteria (NTM) are environmental organisms increasingly recognized as opportunistic pathogens, particularly in immunocompromised individuals. Mycobacterium kansasii, a slow-growing photochromogen (Runyon group I), is primarily associated with pulmonary disease; however, extrapulmonary and cutaneous manifestations are uncommon and often underdiagnosed. Given the rising incidence of NTM infections, cutaneous disease should be considered in the differential diagnosis of skin lesions, especially in immunocompromised patients. Early microbiological confirmation is crucial for appropriate therapy, as M. kansasii is intrinsically resistant to pyrazinamide. Herein, we present a case of pathologically confirmed cutaneous M. kansasii infection occurring in isolation, illustrating the diagnostic challenges and therapeutic outcomes.