%0 Case Reports %T A case of suspected primary mediastinal large B-cell lymphoma: An uncommon cause of sudden death. %A Ben Jomaa S %A Chebbi E %A Ben Hammouda S %A Bel Haj M %A Bouzid O %A Haj Salem N %J Leg Med (Tokyo) %V 64 %N 0 %D 2023 Sep 22 %M 37531821 %F 2.017 %R 10.1016/j.legalmed.2023.102299 %X 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.