弥漫性大B细胞淋巴瘤及血管内大B细胞淋巴瘤患者外周血中肿瘤细胞较少时的血涂片形态学特点及阅片经验分享

Morphological Characteristics and Experience Sharing of Blood Smear in Patients with Diffuse Large B-cell Lymphoma and Intravascular Large B-cell lymphoma with Few Tumor Cells in Peripheral Blood

目的 探讨弥漫性大B细胞淋巴瘤(DLBCL)及血管内大B细胞淋巴瘤(IVLBCL)患者出现外周血侵犯时镜下血细胞形态学特点,分享血涂片阳性检出的阅片方法。方法 回顾分析中国医学科学院北京协和医院2018年6月至2023年7月期间首诊触发血细胞复检规则并进行外周血涂片形态学检查的4例DLBCL确诊患者和8例IVLBCL确诊患者的外周血涂片标本和临床资料。结果 12例患者中不明原因发热10例、盗汗4例、体重下降7例,淋巴结肿大7例、其中全身多处淋巴结肿大5例,肝大2例,脾大8例;以上DLBCL和IVLBCL患者出现外周血侵犯时,使用低倍镜浏览患者外周血涂片可于血膜边缘及尾部残留血边线处见直径达正常淋巴细胞2倍及以上的特征异常淋巴细胞或噬血细胞;该类细胞胞体大,染色质成熟程度不一,可呈条索样排列;细胞核形不规则,可见扭曲、折叠、切迹;胞质呈现强嗜碱性,颗粒少见。结论 血常规提示两系或三系减低时,应查看患者临床病历。若见全身B症状(不明原因持续发热、体重减轻、盗汗),肝、脾或淋巴结肿大,外周血涂片应首先重点查看血膜边缘及残留血边线中是否存在直径大的涂抹细胞、异常淋巴细胞或噬血细胞,然后在低倍镜下浏览血片头部或头体交界处是否存在异常淋巴细胞,以及时提示临床。尤其见噬血细胞时,应警惕淋巴瘤相关的噬血细胞综合征,为患者争取治疗时间。

Objective To explore the morphological characteristics of peripheral blood invasion in patients with diffuse large B-cell lymphoma(DLBCL) and intravascular large B-cell lymphoma(IVLBCL), and to share the methods for detecting positive findings in blood smears. Methods A retrospective analysis was conducted on peripheral blood smear specimens and clinical data from four confirmed cases of DLBCL patients and eight confirmed cases of IVLBCL patients who triggered the blood cell retest rule and underwent peripheral blood smear morphology examination at Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, during the period from June, 2018 to July, 2023. Results Among the 12 patients, 10 showed unexplained fever, 4 presented night sweats, and 7 had weight loss. Lymphadenopathy was observed in 7 patients, including generalized lymphadenopathy in 5 patients, hepatomegaly in 2 patients, and splenomegaly in 8 patients. When peripheral blood invasion occurred in the above DLBCL and IVLBCL patients, abnormal lymphocytes or phagocytes with a diameter of twice or more than that of normal lymphocytes could be observed at the edge and the tail residual line of the blood film under low magnification. These cells had large cell bodies with varying degrees of chromatin maturity and could be arranged in a cord-like pattern. The cell nuclei were irregular and showed twisting, folding, or incisions shapes. The cytoplasm appeared strongly basophilic, with few granules observed. Conclusion When a patient's blood routine triggers test indicates a decrease in two or three blood cell lineages, the patient's clinical history should be examined. If systemic B symptoms(unexplained persistent fever, weight loss, night sweats) are present, along with hepatomegaly, splenomegaly, or lymphadenopathy, the peripheral blood smear should be focused on examining whether there are large smear cells, abnormal lymphocytes, or histiocytes with diameters larger than normal at the blood membrane edge and residual blood margins, then check the whole film at low power to see if there are abnormal lymphocytes on the head or at the head-body junction. This testing pipeline can provide timely clinical indications. Especially when histiocytes are observed, vigilance should be exercised for lymphoma-associated hemophagocytic syndrome, in order to gain valuable time window for treatment.