General Pathology and Cytopathology Unit, Department of Medicine-DIMED, University of Padova, 35121 Padova, Italy.
General Pathology and Cytopathology Unit, Department of Medicine-DIMED, University of Padova, 35121 Padova, Italy.
Hum Pathol. 2018 Nov;81:131-137. doi: 10.1016/j.humpath.2018.06.027. Epub 2018 Jun 30.
Benign terminal deoxynucleotidyl transferase (TdT)-positive cells have been documented in a variety of nonhematopoietic tissues. Scant data are, however, available on their presence in nonneoplastic lymph nodes. This study is aimed to (1) characterize the presence/distribution of benign TdT-positive cells in pediatric and adult reactive lymph nodes and (2) define the phenotype and nature of such elements. This retrospective study considered 141 reactive lymph nodes from pediatric and adult patients without history of neoplastic disease. TdT-positive cells were characterized by immunohistochemical and morphometric analyses, and their presence was correlated with the clinical-pathological features. The nature of TdT-positive cells was investigated by (1) double immunostaining for early lymphoid cell markers and (2) assessment of TdT expression in fetal lymph nodes. Sparse TdT-positive cells were documented in all pediatric cases and in most (76%) adult lymph nodes. TdT-positive cell density was higher in children than adults (15.9/mm versus 8.6/mm; P < .05). TdT positivity did not correlate with any clinical or histological parameter, and double immunostaining disclosed a phenotype compatible with early lymphoid precursors (positivity for CD34 and CD10, and variable expression of CD7). A very high TdT-positive cell density (802.4/mm) was reported in all fetal lymph nodes. In conclusion, TdT-positive cells are a common finding in pediatric and adult lymph nodes. The interstitial distribution and low number of such cells allow for the differential diagnosis with precursor lymphoid neoplasms. The high density in fetal lymph nodes and the phenotype of such cells suggest their belonging to an immature lymphoid subset gradually decreasing with age.
良性末端脱氧核苷酸转移酶 (TdT)-阳性细胞已在多种非造血组织中得到证实。然而，关于其在非肿瘤性淋巴结中的存在，仅有少量数据。本研究旨在：(1) 描述良性 TdT 阳性细胞在儿科和成人反应性淋巴结中的存在/分布；(2) 定义此类细胞的表型和性质。这项回顾性研究纳入了 141 例来自无肿瘤病史的儿科和成年患者的反应性淋巴结。通过免疫组织化学和形态计量学分析来鉴定 TdT 阳性细胞，并将其存在与临床病理特征相关联。通过以下两种方法来研究 TdT 阳性细胞的性质：(1) 对早期淋巴细胞标志物进行双重免疫染色；(2) 评估胎儿淋巴结中的 TdT 表达。在所有儿科病例和大多数(76%)成人淋巴结中都发现了稀疏的 TdT 阳性细胞。儿童的 TdT 阳性细胞密度高于成人(15.9/mm 比 8.6/mm；P <.05)。TdT 阳性与任何临床或组织学参数均无关，双重免疫染色显示与早期淋巴前体细胞一致的表型(CD34 和 CD10 阳性，CD7 表达可变)。所有胎儿淋巴结的 TdT 阳性细胞密度均非常高(802.4/mm)。总之，TdT 阳性细胞是儿科和成人淋巴结中的常见发现。这些细胞的间质分布和数量较少有助于与前体淋巴细胞肿瘤进行鉴别诊断。在胎儿淋巴结中存在高 TdT 阳性细胞密度以及此类细胞的表型表明它们属于逐渐随年龄减少的不成熟淋巴亚群。
