Cutaneous T-Cell Lymphoma-Like Eruption from Trimethoprim-Sulfamethoxazole.

Cutaneous pseudolymphoma is a benign reactive process that comprises a heterogeneous group of entities that resembles lymphoma clinically and/or histologically. This condition can be idiopathic or caused by drugs, infections, or foreign agents. Cutaneous pseudolymphoma could belong to the B-cell type, the T-cell type, or be mixed. The multiple presentations raise a significant diagnostic challenge and require clinicopathologic correlation and follow-up. This case report presents the clinical, histopathologic, immunophenotypic, and genetic findings of a cutaneous T-cell lymphoma-like eruption from trimethoprim-sulfamethoxazole in a 55-year-old female systemic lupus patient.