Makita Masanori, Murakami Ichiro, Yoshioka Takanori, Tanaka Hisaaki, Yamamoto Kazuhiko, Imajo Kenji, Takata Katsuyoshi, Yoshino Tadashi
Department of Hematology, Okayama City Hospital, Japan.
Rinsho Ketsueki. 2009 May;50(5):413-8.
We report a case of extranodal CD20-positive peripheral T-cell lymphoma (PTCL). A 59-year-old man was admitted because of a right testicular mass in April 2006. CT scan revealed bilateral adrenal masses and he underwent right orchiectomy. The enlarged testis showed diffuse infiltration of large CD20-positive lymphocytes with slight CD3-positive cells. These cells were negative for CD10 and showed a high MIB-1 index. The pathological diagnosis was diffuse large B-cell lymphoma. He received R-CHOP, but developed brain involvement. He received whole brain radiotherapy following high-dose methotrexate, but he died of disease progression in August 2007. At autopsy, lymphoma cells were definitely positive for CD3 and negative for CD20. Monoclonal TCR gamma gene rearrangement was detected in the brain specimen without IgH rearrangement by PCR. The testicular tumor also showed the same clonal bands. Immunohistochemical re-evaluation of the testis showed CD20+, CD79a-, PAX5-, MUM1-, CD3 p+, CD5 p+, CD4-, CD8-, CD7 p+, granzyme B+, and TIA1+. Based on the clinical course and immunohistology, we finally diagnosed this case as extranodal PTCL-nos (not otherwise specified) with aberrant CD20 expression, which is extremely rare. The detection of gene rearrangement, plural immunohistochemical markers and knowledge of the possibility of CD20+ PTCL-nos are necessary for such cases.
我们报告一例结外CD20阳性外周T细胞淋巴瘤（PTCL）。一名59岁男性因右侧睾丸肿物于2006年4月入院。CT扫描显示双侧肾上腺肿物，随后他接受了右侧睾丸切除术。肿大的睾丸显示大量CD20阳性淋巴细胞弥漫浸润，伴有少量CD3阳性细胞。这些细胞CD10阴性，MIB-1指数高。病理诊断为弥漫性大B细胞淋巴瘤。他接受了R-CHOP方案化疗，但出现脑转移。在大剂量甲氨蝶呤治疗后，他接受了全脑放疗，但于2007年8月死于疾病进展。尸检时，淋巴瘤细胞CD3呈阳性，CD20呈阴性。通过PCR在脑标本中检测到单克隆TCRγ基因重排，未检测到IgH重排。睾丸肿瘤也显示出相同的克隆条带。对睾丸进行免疫组化重新评估显示CD20阳性、CD79a阴性、PAX5阴性、MUM1阴性、CD3阳性、CD5阳性、CD4阴性、CD8阴性、CD7阳性、颗粒酶B阳性和TIA1阳性。基于临床病程和免疫组化结果，我们最终将该病例诊断为具有异常CD20表达的结外PTCL-nos（未另行指定），这种情况极为罕见。对于此类病例，检测基因重排、多种免疫组化标志物以及了解CD20+ PTCL-nos的可能性是必要的。
