Jiang Changrui, Shi Xiuying, Fan Chuifeng
Department of Pathology, First Affiliated Hospital and College of Basic Medical Sciences, China Medical University, Shenyang, China.
Medicine (Baltimore). 2017 Mar;96(11):e6311. doi: 10.1097/MD.0000000000006311.
Cyclin D1-positive tumor cells are commonly found in mantle cell lymphoma but they are very rare in diffuse large B-cell lymphoma.
CLINICAL FINDINGS/PATIENT CONCERNS: Here we present a rare case of cyclin D1-positive diffuse large B-cell lymphoma in the right tonsil of a 50-year-old man. Computed tomographic imaging detected a mass, about 2.5 cm × 1.8 cm in size, in the left side of the oropharynx.
Microscopically, the tumor cells were located under the pharyngeal mucosa and diffusely arranged. The tumor cells were large, with marked nuclear atypia. On performing immunohistochemistry, the tumor cells showed diffuse positive staining for CD10, CD20, cyclin D1, and Pax-5, and negative staining for CD3, CD15, CD30, CD56, and CK. Bcl-6 and Mum-1 expression were observed in 60% and 80% of tumor cells, respectively. The tumor Ki67 index was about 60%. Based on these findings, The tumor was diagnosed as a rare cyclin D1-positive diffuse large B-cell lymphoma rather than a mantle cell lymphoma.
Cyclin D1-positive large B-cell lymphoma is rare, but as large B-cell lymphoma is a common type of lymphoma, cyclin D1-positive large B-cell lymphoma should be considered a major possibility during differential diagnosis, including in the tonsils.
细胞周期蛋白D1阳性肿瘤细胞常见于套细胞淋巴瘤，但在弥漫性大B细胞淋巴瘤中非常罕见。
临床发现/患者关注问题：在此，我们报告一例罕见的细胞周期蛋白D1阳性弥漫性大B细胞淋巴瘤，发生于一名50岁男性的右侧扁桃体。计算机断层扫描成像在口咽左侧检测到一个大小约为2.5厘米×1.8厘米的肿块。
显微镜下，肿瘤细胞位于咽黏膜下方，呈弥漫性排列。肿瘤细胞体积较大，核异型性明显。进行免疫组织化学检查时，肿瘤细胞对CD10、CD20、细胞周期蛋白D1和Pax-5呈弥漫性阳性染色，对CD3、CD15、CD30、CD56和细胞角蛋白呈阴性染色。分别在60%和80%的肿瘤细胞中观察到Bcl-6和Mum-1表达。肿瘤Ki67指数约为60%。基于这些发现，该肿瘤被诊断为罕见的细胞周期蛋白D1阳性弥漫性大B细胞淋巴瘤，而非套细胞淋巴瘤。
细胞周期蛋白D1阳性大B细胞淋巴瘤罕见，但由于大B细胞淋巴瘤是淋巴瘤的常见类型，在鉴别诊断时，包括在扁桃体病变中鉴别时，应将细胞周期蛋白D1阳性大B细胞淋巴瘤视为主要的可能诊断。
