68196Department of Pathology, Zaloska 2, Ljubljana 1000, Slovenia.
30262University Hospital Basel, University of Basel, Basel, Switzerland.
Int J Surg Pathol. 2022 May;30(3):273-277. doi: 10.1177/10668969211047981. Epub 2021 Nov 5.
NUT carcinoma is a highly aggressive and rare subset of squamous cell carcinoma with grim prognosis. It is under-recognized by both pathologists and oncologists. Recognition is challenging due to its rareness and the fact that its clinical and laboratory features as well as morphological and immunohistochemical characteristics may mimic other malignancies. An interesting case of NUT carcinoma in a 47-year-old male with a large tumor mass in the inferior part of the mediastinum and left lung and increased levels of serum alpha fetoprotein (AFP) is described. Immunohistochemical analysis of both the primary tumor in a bronchoscopy specimen and an excisional biopsy of a subcutaneous metastasis showed positivity for AFP and leukocyte common antigen (LCA) that were misleading and resulted in diagnostic pitfalls of mediastinal germ cell tumor (clinically) and hematolymphoid neoplasm (pathologic report). Immunohistochemical demonstration of NUT protein expression revealed the proper diagnosis, which was further confirmed by RNA sequencing revealing a BRD4- gene fusion. Since NUT carcinoma can show a wide spectrum of histological and immunophenotypic features and can clinically mimic other tumors, use of RNA sequencing with identification of specific fusion partner could be crucial when there are discrepant clinical and histopathological findings. As well, since the category of so-called -rearranged neoplasms is rapidly expanding, identification of fusion partner may be essential for the appropriate clinical management.
NUT 癌是一种具有严峻预后的高度侵袭性和罕见的鳞状细胞癌亚型。它既不为病理学家所认识，也不为肿瘤学家所认识。由于其罕见性，以及其临床和实验室特征以及形态学和免疫组织化学特征可能模仿其他恶性肿瘤，因此识别具有挑战性。描述了一例有趣的 NUT 癌病例，患者为 47 岁男性，中下纵隔和左肺有大肿瘤肿块，血清甲胎蛋白（AFP）水平升高。支气管镜标本和皮下转移灶切除活检的原发性肿瘤的免疫组织化学分析显示 AFP 和白细胞共同抗原（LCA）阳性，这是误导性的，并导致纵隔生殖细胞瘤（临床）和血液淋巴肿瘤（病理报告）的诊断陷阱。NUT 蛋白表达的免疫组织化学显示出正确的诊断，这进一步通过 RNA 测序证实，显示 BRD4-基因融合。由于 NUT 癌可表现出广泛的组织学和免疫表型特征，并且在临床上可模仿其他肿瘤，因此当存在不一致的临床和组织病理学发现时，使用 RNA 测序并鉴定特定的融合伙伴可能至关重要。此外，由于所谓的-重排肿瘤的类别正在迅速扩大，因此鉴定融合伙伴对于适当的临床管理可能至关重要。
