我们介绍一位复发性双侧血胸患者的病例。尽管有多个组织学样本，但仍被误诊，通过进一步的免疫组织学染色诊断出上皮样血管肉瘤的胸膜表现。基于这种情况，我们旨在提高读者对这种罕见疾病的认识。 一名 73 岁意识清醒的女性因呼吸困难 3 天就诊。她的一般状况稳定，否认疼痛，有吸烟史，没有心肺事件，也没有接受任何抗凝药物。体检发现左侧呼吸音减弱，血红蛋白为7.0 mmol/L。初次胸片显示左侧积液。随后诊断为血胸。进一步检查未发现恶性肿瘤的证据（CT、EBUS、细胞学等）。进行了 VATS，胸膜病变活检未显示与血胸一致的结果。由于反复出现双侧血胸，需要输红细胞，患者接受了多次手术，包括组织学取样，没有发现恶性肿瘤的证据。经过进一步处理后，另一份病理报告显示了一种上皮样血管肉瘤，其特征是大量增殖的上皮样细胞，ERG 和 CD31 强阳性，CD34 阴性。肿瘤细胞共表达 D2-40（podoplanin）。最后，由于多发性脑转移，需要姑息治疗。治疗自发性血胸的医生和病理学家需要对可能的、有时是罕见的病因有广泛的了解。如果临床过程和术中发现与组织病理学结果不一致，则必须对这一发现提出质疑，并且必须进行进一步的免疫组织化学染色。因此，在复发性血胸的情况下，还应考虑胸膜血管肉瘤进行鉴别诊断。© 2024 Dörr-Jerat、May、Knolle、Schmidt 和 Krüger。

We present the case of a patient with recurrent bilateral hemothorax. After misdiagnosis despite several histological samples, a pleural manifestation of epithelioid angiosarcoma was diagnosed by further immunohistological staining. Based on this situation, we aim to sensitize the reader to this rare disease.A 73-year-old fully conscious woman presented with dyspnea for 3 days. She was in stable general condition, pain was denied, she had a history of cigarette smoking, she had no cardiopulmonary events, and she was not receiving any anticoagulation medication. Physical examination revealed decreased breath sounds on the left side, and her hemoglobin level was 7.0 mmol/L.The initial chest x-ray showed a left-sided effusion. Hemothorax was then diagnosed. Further investigation revealed no evidence of malignancy (CT, EBUS, cytology, etc.). VATS was performed, and biopsies of pleural lesions did not reveal congruent findings for the hemothorax. Due to recurrent bilateral hemothorax with the need for erythrocyte transfusion, the patient underwent several operations, including histological sampling, without evidence of malignancy. After further processing, an additional pathological report revealed an epithelioid angiosarcoma defined by massively proliferating epithelioid cells strongly positive for ERG and CD31 and negative for CD34. The neoplastic cells coexpressed D2-40 (podoplanin). Finally, due to multiple cerebral metastases, palliative therapy was indicated.Physicians and pathologists treating spontaneous hemothorax need to have broad knowledge of the possible, sometimes rare, etiologies. If the clinical course and intraoperative findings do not agree with the histopathological results, this finding must be questioned, and further immunohistochemical staining is mandatory. Thus, in the case of recurrent hemothorax, angiosarcoma of the pleura should also be considered for differential diagnosis.© 2024 Dörr-Jerat, May, Knolle, Schmidt and Krüger.