Department of Pathology, Northwestern University, Feinberg School of Medicine, Northwestern Memorial Hospital, Chicago, Illinois, USA.
Diagn Cytopathol. 2021 Feb;49(2):E75-E79. doi: 10.1002/dc.24588. Epub 2020 Sep 1.
Pancytokeratins and TTF-1 are used in working up carcinomas of unknown primary and p63 is expressed in many cell lineages. We present a case of a TTF-1, p63, and cytokeratins positive small round blue cell lesion presenting in a patient with enlarged right supraclavicular lymph nodes and multiple solid pulmonary nodules. The preliminary report to the clinical team was "suspicious for carcinoma." However, after a complete work up the final diagnosis of diffuse large B-cell lymphoma, nongerminal center B-cell phenotype, "double expressor," was rendered (based on Han's algorithm). This case brings up significant diagnostic dilemma as some lymphoid malignancies can morphologically mimic poorly differentiated carcinoma and stain positive for carcinoma markers. Additionally, the frequently used TTF-1 SPT23 antibody clone has strong nuclear staining in rare cases of DLBCL, which is a diagnostic pitfall. To our best knowledge this is the first reported case of DLBCL staining positive for three carcinoma markers.
细胞角蛋白和 TTF-1 常用于原发性不明癌的研究，p63 在许多细胞谱系中表达。我们报告了一例 TTF-1、p63 和细胞角蛋白阳性的小圆蓝细胞病变，该病变发生在一名右锁骨上淋巴结肿大和多个实性肺结节的患者中。向临床团队的初步报告是“疑似癌”。然而，经过全面检查，最终诊断为弥漫性大 B 细胞淋巴瘤，非生发中心 B 细胞表型，“双表达”（基于 Han 的算法）。该病例带来了重大的诊断难题，因为一些淋巴恶性肿瘤在形态上可以模拟低分化癌，并对癌标志物呈阳性。此外，常用的 TTF-1 SPT23 抗体克隆在罕见的弥漫性大 B 细胞淋巴瘤中具有强烈的核染色，这是一个诊断陷阱。据我们所知，这是首例报道的弥漫性大 B 细胞淋巴瘤同时表达三种癌标志物的病例。
