CHRONIC, ACTINIC DERMATITIS SIMULATING A FOLLICULAR, LARGE, CLEAVED B-CELL LYMPHOMA

We report a 31-year-old male with a history of chronic photosensitivit y since childhood. Systemic beta-carotene and systemic corticosteroids had improved his condition in the past. Examination revealed red, sca ly plaques with yellow crusts present on sun-exposed skin. A skin biop sy from one of these plaques revealed dermal lymphoid nodules sparing the epidermis. The cells in the center of the lymphoid follicles were CD20 and CD22 positive (CD30 negative). There was no kappa or lambda l ight-chain restriction. The follicles were surrounded by a mantle of s mall lymphocytes composed of T-helper and T-suppressor cells. A diagno sis of malignant B-cell lymphoma of the follicular, large cleaved cell type was suspected. Further laboratory and radiologic evaluations wer e unremarkable. Molecular genetics studies from a skin biopsy detected a clonal immunoglobulin gene rearrangement by polymerase chain reacti on. Phototesting revealed a minimal erythema dose (MED) for UVB and UV A of 5 mJ/cm(2) and 5 J/cm(2), respectively. Typical clinical lesions were reproduced with UVB at 20 mJ/cm(2). The patient improved with sys temic corticosteroids and hydroxychloroquin. To our knowledge, this is the first report in the literature of chronic actinic dermatitis simu lating a cutaneous B-cell lymphoma. This histologic variation should b e kept in mind in patients with chronic actinic dermatitis.