Abstract: The patient,a 11-year-old boy,presented with a 4-year history of erythema and vesicles on the face and arms as well as a 4-month history of tumor and ulcer on the extremities,accompanied by progressive fatigue and intermittent fever.The patient had a body temperature of 37.7℃.No lymph node involvement was observed.Cutaneous examination revealed minimally indurated pink-red patches on the face and nose and dusky red firm nodules and tumors of varying sizes on the extremities.The nodules ranged from 2.0 cm to 18 cm in diameter,some had necrosis and black crusts on the surface.Ulcers were observed in some of the larger nodules;many of the ulcers extended into the muscle layer.White purulent discharge was seen on the surface of many of the nodules.The lesions were sharply demarcated,firm,tender, and surrounded by small satelite nodules.Histologically,there were large quantities of irregularly shaped, middle-sized tumor cells with clear cytoplasm,large twisted nuclei and prominent chromatin,infiltrating from the epidermis to subcutaneous tissue.The tumor cells infiltrating the follicles and eccrine sweat glands were either distributed perivascularly in a nest shape,or dispersed.There were broken nuclei and reactive histiocytic infiltration in the dermis and subcutaneous tissue.Immunohistologically,the tumor cells were positive for cytoplasmic CD3 around the nuclei,for CD56,CD45RO and T cell intracellular antigen-l,and partly for CD30,CD8 and Ki67.Epstein-Barr virus-encoded nuclear RNA was positive with in situ hybridization. TCRγ-2 gene rearrangement was positive in these tumor cells.A diagnosis of hydroa vacciniforme-like primary cutaneous NK/T-cell lymphoma was made.Therefore,this is a case report of hydroa vacciniforme-like primary cutaneous NK/T-cell lymphoma with primary involvement in the skin;the condition was slowly progressive over 51 months.

Key words: Lymphoma, Killer cells,natural, Herpesvirus 4,human, Epstein-Barr virus infections