[Clinicopathological features of indolent T-cell lymphoproliferative disorder of the gastrointestinal tract: a report of five cases].

Objective: To investigate the clinicopathological features of indolent T-cell lymphoproliferative disorder of the gastrointestinal tract. Methods: Five cases of indolent T-cell lymphoproliferative disorder of the gastrointestinal tract from the Affiliated Hospital of Qingdao University from 2016 to 2019 were retrospectively reviewed. The clinical and pathological parameters were analyzed by combining clinical data and reviewing the available literature of 35 cases (34 cases abroad and 1 case in China). Results: There were 4 males and 1 female with a median age of 47 years (18-66 years). All patients had abdominal pain and constitutional symptoms including diarrhea, emaciation, intermittent mucous stool or oral and epiglottic ulcers. Endoscopic manifestations included multiple punctate congestion, erosion and ulcer at the terminal ileum and colorectum. Two cases had congestion and erosion of antrum and angle of stomach, and the lesions did not fuse and form tumors. Histologically, the lamina propria was expanded by a dense, medium to small lymphocyte infiltration, which was monomorphic, with slightly irregular nuclei without prominent nucleolus or lymphoepithelial lesions. There were admixed small amount of plasma cells and eosinophils. In 4 cases, immunohistochemistry showed the lesional cells were positive for CD3, CD8, TIA1, and negative for CD4, CD56, granzyme B and Ki-67 index was ≤10%. In situ hybridization showed that EBER was negative and clonal TCR gene rearrangement was detected. One consultation case was CD3(+), CD5(-) and Ki-67 index of 10%, although other indicators were not done. All five patients were treated with symptomatic support. In follow-up observation for 2 to 25 months, all patients were alive with the disease. Conclusions: Indolent T-cell lymphoproliferative disorder of the gastrointestinal tract is a newly classified monoclonal T-cell proliferative disease, with low incidence, clinical inertia and long-term survival. It has unique clinicopathological features but pathologically it is easily misdiagnosed as inflammatory bowel disease or T-cell lymphoma. Correct diagnosis is of great important clinical significance.目的： 探讨胃肠道惰性T细胞淋巴组织增殖性疾病的临床病理特征。 方法： 收集2016至2019年青岛大学附属医院病理科诊断的5例胃肠道惰性T细胞淋巴组织增殖性疾病，结合临床资料并复习目前报道的35例（国外34例，国内1例）文献资料，分析该疾病的临床病理特点。 结果： 患者5例，男性4例，女性1例，中位年龄47岁（18~66岁）。临床均以腹痛就诊，可伴有腹泻、消瘦、间断黏液便或口腔、会厌溃疡。消化道内镜表现为回肠末端、结直肠多发点状充血、糜烂、溃疡，其中2例伴胃窦、胃角充血和糜烂，病变不融合、不形成肿物。肠镜活检组织光镜下见黏膜固有层弥漫致密的中等偏小的淋巴细胞浸润，形态单一，细胞核轻度不规则，无核仁，无淋巴上皮病变，可见少量浆细胞与嗜酸性粒细胞浸润。4例患者免疫组织化学CD3、CD8、T细胞胞质内抗原1均阳性，CD4、CD56、颗粒酶B均阴性，Ki-67阳性指数≤10%，原位杂交EBER阴性，T细胞受体基因重排阳性；1例会诊病例CD3阳性、CD5阴性、Ki-67阳性指数约10%，其余指标未做。5例患者对症支持治疗并随访观察2~25个月，均带病生存。 结论： 胃肠道惰性T细胞淋巴组织增殖性疾病是一种单克隆性T淋巴细胞增生性病变，发病率低，临床呈惰性过程，可长期存活，有独特的临床病理特征，易误诊为炎症性肠病或T细胞淋巴瘤，正确的病理诊断和对该病变的认识具有重要的临床意义。.