Stenotrophomonas maltophilia–associated primary cutaneous anaplastic large-cell lymphoma

Bacteria have long been considered drivers in the development of cutaneous lymphoma, as bacterial antigens may encourage reactive, dysregulated lymphocytic proliferation.1,2 For example, Staphylococcus aureus infection has been implicated in the pathogenesis of mycosis fungoides and Sezary syndrome, whereas Borrelia burgdorferi is clinically associated with primary cutaneous B-cell lymphoma.3, 4, 5, 6, 7 Stenotrophomonas maltophilia is an opportunist gram-negative bacterium, primarily recognized as a cause of nosocomial infection among immunocompromised individuals.8 Ste maltophilia, specifically, has been associated with breast implant–associated anaplastic large-cell lymphoma (BIA-ALCL),9,10 and it has also been reported to be an antigenic driver in cutaneous pseudolymphoma.11 We report a new association of primary cutaneous anaplastic large-cell lymphoma (PC-ALCL) with Ste maltophilia in otherwise immunocompetent men.