Supplementary Material for: Primary pleural epithelioid angiosarcoma with lung and bone metastases: a case report

Introduction：Primary pleural epithelial angiosarcoma (EAS) is an extremely rare tumor with no specific clinical symptoms. Clinical data on primary pleural EAS are limited, and misdiagnosis often occurs.Case Presentation:The present study reports the case of a 31-year-old patient diagnosed with primary pleural EAS with lung and bone metastases. The patient presented with persistent right chest pain for five months and dyspnea for two months. Chest CT scan revealed right hydropneumothorax, diffuse thickening of the right pleura, passive atelectasis, and scattered nodules in the left lung. A medical thoracoscopic pleural biopsy revealed a vasogenic tumor. To further confirm the diagnosis,positron emission tomography/computedtomography(PET/CT) examination was recommended to determine the biopsy site after multidisciplinary discussion. Increased 18F-FDG uptake in the right pleura and hypermetabolic nodules in the right chest wall, L1, S2, and bilateral iliac crest were detected via PET/CT. CT-guided chest wall and lung biopsies were performed. Immunohistochemistry of specific markers was performed according to remote consultation with a pathologist, and tumor cells with strong positive expression of CD31, CD34, and ERG led to the final diagnosis of primary pleural EAS.Conclusion: Primary pleural EAS should be considered for hydropneumothorax of unknown cause; PET/CT can accurately locate the lesion; the pathological examination is the basis for Primary pleural EAS diagnosis; moreover, multidisciplinary discussion and remote expert consultation can improve the diagnosis rate of primary pleural EAS.