外周NK/T细胞淋巴瘤（ENKTL）是一种非霍奇金淋巴瘤的亚型，主要由NK细胞和罕见的T细胞演化而来。当遇到非典型表型和基因重排时，诊断会带来一定的挑战。本文报道了一例表达CD20和IGH基因重排的ENKTL，这是极为罕见的情况。一名57岁的女性患者于2021年因左腿结节和同时出现6个月的视力受损而就诊。进行了皮肤活检和免疫组化检查。淋巴细胞CD3、CD56、灵素B和TIA-1呈阳性，部分阳性表达CD2，轻度阳性表达CD20。Epstein-Barr病毒的原位杂交检测呈阳性。分子研究显示出免疫球蛋白重链（IGH）基因重排，而未检测到T细胞受体基因重排。正电子发射断层扫描显示患者双侧肾上腺、盆腔、腹腔、小肠、皮肤和下肢皮下组织受到淋巴瘤的影响。尽管接受了八个疗程的化疗和放疗，但患者的病情仍然进展。这个案例的重要性在于非典型表型和IGH基因重排，要求对临床病理数据进行综合解读。© 2023 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Extranodal NK/T-cell lymphoma (ENKTL) is a subtype of non-Hodgkin lymphoma mainly derived from NK cells and, uncommonly, T-cells. A diagnostic challenge is presented when an atypical phenotype and gene rearrangement are encountered. Herein, we report a case of ENKTL with CD20 expression and IGH gene rearrangement, which is extremely rare. A 57-year-old female patient was seen in 2021 due to a nodule on her left leg and simultaneously impaired eyesight for 6 months. Skin biopsy and immunohistochemistry were performed. The lymphoid cells were positive for CD3, CD56, granzyme B, and TIA-1, partially positive for CD2, and mildly positive for CD20. In situ hybridization for Epstein-Barr virus was positive. Molecular studies revealed immunoglobulin heavy chain (IGH) gene rearrangement, while no T-cell receptor gene rearrangement was detected. The positron emission tomography scan showed that the lymphoma affected bilateral adrenal glands, pelvic cavity, peritoneal cavity, small intestine, skin, and subcutis of the bilateral lower extremities of the patient. Her disease progressed despite eight cycles of chemotherapy and radiation therapy. The importance of this case lies in the atypical phenotype and IGH gene rearrangements, necessitating comprehensive interpretation of clinicopathological data.© 2023 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.