小细胞性非特指外周T细胞淋巴瘤病理形态和免疫表型分析

目的 探讨小细胞性非特指外周T细胞淋巴瘤(PTCL,NOS)的临床病理与免疫表型及其病理诊断和鉴别诊断.方法 对5例小细胞性PTCL,NOS进行临床病理回顾性研究和随访,免疫表型检测(SP和EnVision法),以及EBER原位杂交和T细胞受体(TCR)基因重排分析.结果 5例均为男性,平均年龄52.6岁.中位病程1个月.5例中3例为临床Ⅳ期,2例为临床Ⅲ期.4例有全身浅表淋巴结及脾脏肿大,1例有肝肿大.2例有浆膜腔积液.行骨髓检查的4例中,3例有肿瘤累及.1例有外周血自细胞总数和淋巴细胞分类计数升高.主要病理改变为淋巴结结构的破坏和单一形态的小淋巴细胞弥漫性浸润,4例可见少数大的异形细胞散在分布,2例见小血管增生现象.5例之肿瘤细胞均表达两种以上T细胞分化抗原和CD43,表达CD99(3/4),均不表达CD20、末端脱氧核苷酸转移酶、CD56和粒酶B.Ki-67指数为5%-15%.4例行TCR基因重排分析,均存在TCRy基因克隆性重排,1例检出TCRβ基因克隆性重排.EBER原位杂交检测均为阴性.获得3例随访资料,且患者均死亡,平均生存时间21.7个月.结论 小细胞性PTCL,NOS少见,呈高临床分期,预后差,组织形态表现为惰性淋巴瘤.

Small cell variant of peripheral T-cell lymphoma, not otherwise specified: a clinicopathologic and immunophenotypic analysis

Objective To study the clinicopathologic features and differential diagnosis of small cell variant of peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS).Methods The clinicopathologic features of 5 cases of small cell variant of PTCL, NOS were retrospectively reviewed, with immunohistochemical study, T-cell receptor(TCR) gene reatrangement analysis and evaluation for Epstein-Barr virus (EBV) status. Results All the 5 patients were males. The mean age was 52. 6 years. The median duration before diagnosis was 1 month. Clinically, 3 patients presented in stage Ⅳ and 2 in stage Ⅲ. Four of them had generalized lymphadenopathy and splenomngaly. Hepatomegaly and massive effusion were found in 1 and 2 cases, respectively. Marrow involvement was detected in 3 of the 4 patients with bone marrow biopsy performed and one of them also accompanied by lymphocytesis. Histologically, the involved lymph nodes showed partial or complete effacement of nodal architecture and replacement by a monomorphous population of small lymphoid cells. Scanty large lymphoid cells were also identified in 4 cases. Increase in number of blood vessels was noticed in two of them as well. Immunohistochemically, the lymphoma cells in all cases expressed two or more of the T-cell markers and CD43. The staining for CD20, TdT, CD56 and granzyme B was negative. CD99 expression was noted in 3 of the 4 cases. The Ki-67 index ranged from 5% to 15%. Clonal TCRy gene rearrangement was detected in the 4 cases studied and one of them also showed TCRβ gene rearrangement, In-situ hybridization for EBV-encoded RNA was negative in the 4 cases studied.Follow up information was available in 3 of the 5 cases. All of the 3 patients died of the disease, with an average survival of 21.7 months. Conclusion Small cell variant of PTCL, NOS represents a rare disease entity which often presents in advanced tumor stage and carries a poor prognosis.