淋巴结增生和淋巴瘤中滤泡树突细胞网型分类及其在鉴别诊断中的作用

Classification of follicular dendritic cell meshwork pattern and its role in differential diagnosis of lymphoid hyperplasia from lymphoma

目的探讨滤泡树突细胞网型(follicular dendritic cell meshwork pattern,FDCMP)在淋巴结增生和淋巴瘤中的不同形态分类及其鉴别诊断作用。方法收集淋巴结标本85例,包括淋巴结滤泡增生20例、副皮质区增生10例、透明血管型Castleman病5例、不同级别滤泡性淋巴瘤15例、套细胞淋巴瘤5例、边缘区淋巴瘤5例、T区淋巴瘤3例、非生发中心B细胞型弥漫大B细胞淋巴瘤10例、血管免疫母细胞性T细胞淋巴瘤12例,所有病例除行常规免疫组化染色外,均行CD21免疫组化染色;其中12例行Ig H与TCRγ基因重排检测。每例病变依据HE染色及免疫组化染色形态进行FDCMP分类。结果反应性增生型FDCMP:包括生发中心A型、生发中心B型、祼生发中心型、极性型、多生发中心型和变性型;不典型增生型;肿瘤型FDCMP包括殖入型、网内增殖爆裂型、滤泡外围血管滤泡树突细胞增殖网型及结节增殖型。反应性增生型FDCMP完整,周界清晰,网格规则无破坏;肿瘤型FDCMP有不同程度的破坏,周界不清,网格破碎;不典型增生型FDCMP介于二者之间。结论结合病理组织学、免疫表型及分子病理检测,综合评价3类FDCMP形态变化的差异,可作为淋巴结病变良、恶性鉴别诊断有效的参考指标之一。

Purpose To explore the different classification of follicular dendritic cell meshwork pattern （FDCMP） and its roles in the differential diagnosis of hyperplasia of lymph node from lymphoma. Methods 85 cases node lymph were collected from surgical pathology archives, including 20 cases of follicular hyperplasia, 10 paracortex hyperplasia, 5 Castleman disease （hyaline-vascular type）, 15 follicular lymphoma in different grades, 5 mantle cell lymphoma, 5 marginal zone lymphoma, 3 T-zone lymphoma, 10 non-GCB diffuse large B cell lymphoma and 12 cases of angioimmunoblastic T cell lymphoma. In addition to the common immunohistochemical markers, all the cases were also stained with CD21, and 12 cases had IgH and TCR~, gene rearrangement analysis. The different types of FDCMP were classified according to the morphology changes of HE stain and immunostaining among these 85 cases, with discussion on the roles of differential diagnosis between benign and malignant lymphadenopathy. Results Reactive hyperplasia type of FDCMP included germinal center-pattern A, germinal center-pattern B, null germinal center pattern, polarized pattern, multi-germinal center pattern and degenerative pattern, atypical hyperplasia type of FDCMP was noted. Tumor type of FDCMP included colonized pattern, intrameshwork proliferation burst pattern, extrafollicular around vessel of FDC proliferative meshwork pattern and nodular proliferative pattern. Reactive hyperplasia type of FDCMP was well-circumscribed with regular meshwork, while it was poorly-circumscribed with fractured meshwork in tumor type of FDCMP. Atypical hyperplasia type of FDCMP was between these two types of FDCMP. Conclu- sion To assess the difference among the 3 types of FDCMP we should combine morphology with immunohistochemistry and molecular testing. FDCMP can be used as one of the effective indexes for differential diagnosis of benign from malignant lymphoid proliferations.