Department of Pathology, Showa University School of Medicine, Tokyo, Japan.
Hospital Pathology Division, Kyorin University Hospital, Tokyo, Japan.
Diagn Cytopathol. 2021 Jul;49(7):842-849. doi: 10.1002/dc.24753. Epub 2021 Apr 20.
In Fine-needle aspiration cytology (FNAC) of lymph nodes, tissue fragments derived from follicular structures may be observed in specimens. We defined such tissue fragments as follicular tissue fragments (FTF), and investigated differences in cytological findings for FTFs of each histological type.
A total of 41 cases with FNAC of lymph nodes were examined. In these cases, the histopathological diagnoses were reactive lymphoid hyperplasia (RLH) (n = 17), follicular lymphoma (FL) (n = 13), diffuse large B-cell lymphoma (DLBCL) (n = 18), and Burkitt lymphoma (n = 1). Specimens were analyzed for the presence of FTFs, and for tingible-body macrophages (TBMs) and monomorphism of lymphocytes in FTFs. FTFs with a maximum diameter of >500 μm were defined as large-FTFs.
FTFs were identified in RLH (14/17, 82.4%), FL (13/13, 100%), and DLBCL (3/18, 16.7%). In the RLH subtypes, FTFs were present only in follicular hyperplasia (FH) (14/15, 93.3%) and not in paracortical hyperplasia (0/2). The number of cases with large FTFs among those with FTFs were as follows: RLH (10/14, 71.4%), FL (11/13, 84.6%), and DLBCL (0/3). Similarly, those with TBMs in FTFs were as follows: RLH (13/14, 92.9%), FL (0/13) and DLBCL (2/3, 66.7%). Monomorphism was observed in RLH (1/14, 7.1%) and FL (11/13, 84.6%), but not in DLBCL (0/3).
Distinction between FL and FH is possible by identifying large-FTFs. In FL, TBMs are absent in FTFs and lymphocytes often show monomorphism. Therefore, recognizing FTFs and observing details inside the FTFs are useful for identification and differential diagnosis of FL and FH in FNAC of lymph nodes.
在细针穿刺细胞学（FNAC）的淋巴结中，组织碎片可能来源于滤泡结构，观察到标本。我们将这些组织碎片定义为滤泡组织碎片（FTF），并研究了每种组织类型的 FTF 的细胞学差异。
共检查了 41 例淋巴结 FNAC 病例。这些病例的组织病理学诊断为反应性淋巴组织增生（RLH）（n=17）、滤泡淋巴瘤（FL）（n=13）、弥漫性大 B 细胞淋巴瘤（DLBCL）（n=18）和伯基特淋巴瘤（n=1）。分析标本中是否存在 FTF 以及 FTF 中的含铁血黄素巨噬细胞（TBM）和淋巴细胞形态单一性。最大直径>500μm 的 FTF 定义为大 FTF。
在 RLH（14/17，82.4%）、FL（13/13，100%）和 DLBCL（3/18，16.7%）中均发现 FTF。在 RLH 亚型中，仅在滤泡增生（FH）（14/15，93.3%）中存在 FTF，而在副皮质增生（0/2）中不存在。有 FTF 的病例中，大 FTF 的数量如下：RLH（10/14，71.4%）、FL（11/13，84.6%）和 DLBCL（0/3）。同样，在 FTF 中存在 TBM 的病例如下：RLH（13/14，92.9%）、FL（0/13）和 DLBCL（2/3，66.7%）。形态单一性见于 RLH（1/14，7.1%）和 FL（11/13，84.6%），但在 DLBCL（0/3）中未见。
通过识别大 FTF，可以区分 FL 和 FH。在 FL 中，FTF 中不存在 TBM，淋巴细胞常表现为形态单一性。因此，识别 FTF 并观察 FTF 内的细节，对 FNAC 淋巴结中 FL 和 FH 的鉴别诊断有帮助。
