Successful treatment of secondary NK/T-cell lymphoma of the testis

Abstract

Dear Editor, Extranodal natural killer/T-cell lymphoma (NTCL) is a rare subtype of non-Hodgkin’s lymphoma that is more prevalent in Asian and Latin American countries than in Western countries [1, 2]. The disease is generally associated with Epstein–Barr virus (EBV) infection. In recent years, chemotherapy with dexamethasone, etoposide, ifosphamide, and carboplatin (DeVIC) has come to be approved for the treatment of limited-stage nasal NTCL. DeVIC therapy in combination with concurrent radiotherapy for localized nasal NTCL resulted in a 2-year overall survival rate of 78 % [3]. However, its efficacy against NTCL outside the nasal cavity has not been fully elucidated. We report herein a case of secondary NTCL of the testis that was successfully treated with unilateral orchiectomy, DeVIC therapy, and radiotherapy to the contralateral testis. A 73-year-old male was referred to our institution because of skin rash in the left thigh and left flank (Fig. 1a). He had a medical history of nasal NTCL which had been treated with local radiotherapy at a total dose of 40 Gy. Laboratory data were unremarkable except for a slightly increased soluble interleukin-2 receptor level of 635 U/ml. F18 fluorodeoxyglucose (FDG)-positron emission tomography (PET) identified uptakes in the right testis and left flank (Fig. 1b). Histological findings of the skin were notable for proliferation of lymphoid cells with cleaved nuclei. Immunostaining showed that the cells were CD3+, CD56+, CD20–, Granzyme B+, and TIA+. EBV-encoded small RNA (EBER)-in situ hybridization (ISH) had a positive result. Since involvement of the right testis was strongly suspected, the patient underwent right orchiectomy. Light microscopic examination of the right testis revealed total effacement of the normal structure by medium-sized lymphoid cells (Fig. 1c). Focal coagulative necrosis was occasionally recorded. The immunophenotype of the neoplastic cells was the same as that of the skin lesion. EBER-ISH was positive. Taken together, the patient was diagnosed with secondary testicular NTCL spreading into the skin. Treatment was initiated with four cycles of DeVIC therapy, which was followed by radiotherapy to the left testis at a total dose of 30 Gy in 15 fractions. FDG-PET after the treatment confirmed complete remission. He has been free from relapse for 4 years. T. Kobayashi :A. Hangaishi :G. Yamamoto :A. Shinohara : Y. Imai : F. Nakamura :M. Kurokawa (*) Department of Hematology and Oncology, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8655, Japan e-mail: kurokawa-tky@umin.ac.jp