Hashmi Atif A, Iftikhar Syeda N, Nargus Gul, Ahmed Omer, Asghar Ishaq Azeem, Shirazi Umme Aiman, Afzal Anoshia, Irfan Muhammad, Ali Javaria
Pathology, Liaquat National Hospital and Medical College, Karachi, PAK.
Pathology, Khyber Medical University, Peshawar, PAK.
Cureus. 2021 Feb 4;13(2):e13120. doi: 10.7759/cureus.13120.
Introduction Diffuse large B-cell lymphoma (DLBCL) is an aggressive B-cell lymphoma. The 2016 World Health Organization (WHO) update on hematopoietic tumors suggested that all DLBCL cases should be subtyped into germinal and non-germinal center phenotypes. Ki67 immunohistochemistry is a maker of cell proliferation and thus is used as a prognostic and predictive marker in various tumors of human body. Only a few studies evaluated the proliferative index of DLBCL subtypes in our population. Therefore, in this study, we evaluated the frequency of subtypes of DLBCL in our population and K67 index in each subtype. Methods A retrospective observational study was conducted in the Department of Histopathology, Liaquat National Hospital and Medical College, from January 2018 till December 2020, over a period of three years. A total of 101 cases with a histopathological diagnosis consistent DLBCL were included in the study. Immunohistochemical (IHC) stains CD10, B-cell lymphoma 6 (Bcl-6), and multiple myeloma oncogene 1 (MUM1) were applied for the further sub-categorization of DLBCL into germinal center B-cell-like (GCB) and non-GCB subtypes according to the Hans algorithm. The Ki67 index was interpreted in hot spots of the tumor and reported as an average percentage. Results Out of 101 DLBCL cases, 47.5% of DLBCL were GCB, while 52.5% were non-GCB subtypes. Bcl-2, Bcl-6, MUM1, c-Myc, CD10, and CD30 expression were noted in 62.4%, 45.5%, 42.6%, 44.6%, 39.6%, and 7.9% cases, respectively. The mean Ki67 index was 72.94±16.69%. The mean Ki67 index in non-GCB-type DLBCL was 77.67±14.80%, which was significantly higher than the mean Ki67 index in GCB-type DLBCL (67.70±17.22%) with a significant p-value (p=0.002). Cervical lymph node was the most common site of DLBCL, while the stomach was the most common extra-nodal site. A significant association of Ki67 index was noted with subtypes of DLBCL. A higher proportion of non-GCB-type DLBCL exhibited greater than 80% Ki67 index than GCB subtype DLBCL. Moreover, a significant association Ki67 index was noted with c-Myc positivity. A higher proportion of c-Myc-positive DLBCL had greater than 80% Ki67 index. Conclusion We found that non-GCB-type DLBCL had a higher Ki67 index than GCB subtype DLBCL, portending a poor prognostic significance of non-GCB subtype of DLBCL. Moreover, c-Myc expression was associated with a higher Ki67 index.
引言 弥漫性大B细胞淋巴瘤（DLBCL）是一种侵袭性B细胞淋巴瘤。2016年世界卫生组织（WHO）关于造血肿瘤的更新表明，所有DLBCL病例都应分为生发中心型和非生发中心型。Ki67免疫组化是细胞增殖的标志物，因此在人体各种肿瘤中用作预后和预测标志物。在我们的人群中，只有少数研究评估了DLBCL亚型的增殖指数。因此，在本研究中，我们评估了我们人群中DLBCL亚型的频率以及各亚型中的K67指数。
方法 2018年1月至2020年12月期间，在利亚卡特国家医院和医学院组织病理学系进行了一项为期三年的回顾性观察研究。该研究共纳入101例组织病理学诊断为DLBCL的病例。应用免疫组化（IHC）染色CD10、B细胞淋巴瘤6（Bcl-6）和多发性骨髓瘤癌基因1（MUM1），根据汉斯算法将DLBCL进一步细分为生发中心B细胞样（GCB）和非GCB亚型。在肿瘤的热点区域解读Ki67指数，并报告为平均百分比。
结果 在101例DLBCL病例中，47.5%为GCB型，而52.5%为非GCB亚型。Bcl-2、Bcl-6、MUM1、c-Myc、CD10和CD30的表达分别见于62.4%、45.5%、42.6%、44.6%和7.9%的病例。平均Ki67指数为72.94±16.69%。非GCB型DLBCL的平均Ki67指数为77.67±14.80%，显著高于GCB型DLBCL的平均Ki67指数（67.70±17.22%），p值具有显著性（p=0.002）。颈部淋巴结是DLBCL最常见的部位，而胃是最常见的结外部位。Ki67指数与DLBCL亚型之间存在显著关联。非GCB型DLBCL中Ki67指数大于80%的比例高于GCB亚型DLBCL。此外，Ki67指数与c-Myc阳性之间存在显著关联。c-Myc阳性的DLBCL中，Ki67指数大于80%的比例更高。
结论 我们发现，非GCB型DLBCL的Ki67指数高于GCB亚型DLBCL，这预示着DLBCL的非GCB亚型预后不良。此外，c-Myc表达与较高的Ki67指数相关。
