弥漫性大 B 细胞淋巴瘤 (DLBCL) 是非霍奇金淋巴瘤最常见且最具侵袭性的亚型。患有其他淋巴瘤（例如蕈样肉芽肿 (MF)）的患者患 DLBCL 的总体风险会增加。在本报告中，我们介绍了一名患有早期 MF 的 81 岁女性，她同时进展到肿瘤期、大细胞转化 (LCT) MF，并在淋巴结 (LN) 中发展为原发性 DLBCL。她的腿部出现肿瘤，右腋窝出现新的淋巴结肿大。肿瘤的皮肤活检显示真皮中有大量非典型 CD3、CD4 和 CD30 细胞以及一小部分 CD8 细胞浸润，这与 LCT MF 一致。腋窝淋巴结活检显示弥漫性 CD20、BCL-2、c-MYC 和 CD10- 细胞，高度提示双表达 DLBCL。高通量测序揭示了皮肤肿瘤中的单克隆 T 细胞和淋巴结中的单克隆 B 细胞群。上述发现导致LCT MF和淋巴结双表达DLBCL的同时诊断。我们的病例证明了对出现淋巴结病的皮肤 T 细胞淋巴瘤患者进行全面病理检查的重要性。© 2024 作者。约翰·威利出版的《皮肤病理学杂志》

Diffuse large B-cell lymphoma (DLBCL) is the most common and aggressive subtype of non-Hodgkin lymphoma. The overall risk of developing DLBCL is increased in patients with other lymphomas, such as mycosis fungoides (MF). In this report, we present an 81-year-old female with early-stage MF who simultaneously progressed to tumor stage, large-cell transformed (LCT) MF and developed a primary DLBCL in a lymph node (LN). She presented with a tumor on her leg and new lymphadenopathy in her right axilla. Skin biopsy of the tumor revealed infiltration of large atypical CD3+, CD4+, and CD30+ cells, and a smaller portion of CD8+ cells in the dermis, consistent with LCT MF. Biopsy of the axillary LN revealed diffuse sheets of CD20+, BCL-2+, c-MYC+, and CD10- cells, highly suggestive of double expressor DLBCL. High-throughput sequencing revealed monoclonal T cells in the skin tumor and a monoclonal B-cell population in the LN. The above findings led to simultaneous diagnoses of LCT MF and nodal double expressor DLBCL. Our case demonstrates the importance of performing a full pathological workup in cutaneous T-cell lymphoma patients presenting with lymphadenopathy.© 2024 The Author(s). Journal of Cutaneous Pathology published by John Wiley & Sons Ltd.