NK-/T-cell lymphoma resembling hydroa vacciniforme with positive CD4 marker expression: a diagnostic difficulty.

A 35-year-old Chinese woman presented with a 2.5-year history of facial swelling in the left lower quadrant and a 10-month history of relapsing red papules and vesicles in the perioral area resembling hydroa vacciniforme. Histologically, a tissue biopsy showed a dense infiltration of medium-sized atypical lymphocytic cells expressing CD4 and CD56. A diagnosis of cutaneous NK-/T-cell lymphoma was made. The patient was treated with alpha-interferon, valaciclovir hydrochloride, and low-dose prednisone for 2 months. Her skin lesions and lymphoadenopathy resolved initially, but she succumbed to the disease shortly after starting chemotherapy treatment 11 months later. To our knowledge, this is the first case of CD4CD56 NK-/T-cell lymphoma with clinical features resembling hydroa vacciniforme.