原发性纵隔巨大B细胞淋巴瘤（PMLBCL）是源自胸腺B细胞的侵袭性肿瘤。临床上，它表现为一般的症状，如咳嗽、胸痛和呼吸困难。虽然这些症状并不特异，但严重到足以揭示疾病。我们报告了一例尸检病例，患者为一名25岁男性，曾有咳嗽和呼吸困难的病史，曾两次前往急诊科但未做出诊断。他突然在急诊科出现呼吸困难，随后失去意识。在请求法医尸检后，不久他被宣布死亡。在外部检查中，未发现身体外伤，但发现面部和耳朵有明显的紫绀。尸检中发现了一个纵隔肿块，大小为19 cm × 25 cm，重600 g，向颈下区域和胸廓蔓延，并浸润心包。气管有部分阻塞的淋巴结肿块引起的坏死性黏膜炎。基于病理学和免疫组化学结果，怀疑为原发性纵隔巨大B细胞淋巴瘤。最终，死因被归因于由于这种肿瘤导致的呼吸衰竭。版权所有© 2023 Elsevier B.V. 保留所有权利。

Primary mediastinal large B-cell lymphoma (PMLBCL) is an aggressive tumor originating from thymic B-cells. Clinically, it presents with general signs such as cough, chest pain and dyspnea. Although these symptoms are not specific, they are severe enough to reveal the disease. We report an autopsy case of a 25-year-old man, with a recent past history of cough and dyspnea, for which he consulted twice the emergency department and no diagnosis was made. He presented to the Emergency Unit, with a sudden onset of a dyspnea followed by a loss of consciousness. He was shortly declared dead after, a medico-legal autopsy was requested. On external examination, no traumatic lesions on the body were found, an important cyanosis of the face and ears, was, however, found. On autopsy, a mediastinal mass was found, measuring 19 cm × 25 cm and weighing 600 g, extending to the infra-hyoid region and to the thoracic cage and infiltrating the pericardium. Trachea had a necrotic mucosa with a partially obstructive lymph node mass. The diagnosis of a primary mediastinal large B-cell lymphoma was suspected based on pathological and immunohistochemical findings. The cause of death was finally attributed to respiratory failure due to this tumor.Copyright © 2023 Elsevier B.V. All rights reserved.