Nontuberculous mycobacteria (NTM), which rarely cause cutaneous lesions, are a heterogeneous group of acid-fast bacilli other than Mycobacterium tuberculosis and Mycobacterium leprae. Among the cutaneous NTM infections, Mycobacterium marinum is the most common pathogen and its clinical manifestation can be variable. A 74-year-old woman presented with diffuse tender erythematous to yellow cellulitis-like patches on the left arm along the discrete papules on the left flank. Histopathologic findings showed caseating granuloma that distinctly had central necrosis with a palisaded lymphohistiocytic infiltration and multinucleated giant cells in the upper dermis. Non-caseating granulomas, nonspecific mixed cell infiltration in the deep dermis, and abscesses in the subcutaneous tissue were seen. Cultures for the NTM and sequencing of the polymerase chain reaction confirmed M. marinum infection. Retrospectively, acid-fast bacilli were found in the Ziehl-Neelsen stain. On the basis of histopathologic, microbiologic, and molecular findings, the diagnosis of cutaneous NTM infection caused by M. marinum was made. Among the variable clinicohistopathologic features of cutaneous NTM infection, cellulitis-like appearance is rarely observed and caseating granuloma surrounded by palisading lymphohistiocytic infiltration is not common. Herein, we report a case of unusual clinicohistopathologic features of cutaneous NTM infection caused by M. marinum.