Metastatic Epithelioid Angiosarcoma in Pleural Fluid Complicating Lung Adenocarcinoma: A Case Report

EAS exhibits distinctive cytological features, combined with immunocytochemical staining, that can facilitate the diagnosis of such conditions. Metastatic epithelioid angiosarcoma involving pleural effusion is exceedingly rare. This case describes a patient with malignant pleural effusion from metastatic epithelioid angiosarcoma and a synchronous primary lung adenocarcinoma proven by percutaneous lung biopsy, highlighting the need for careful pathological differentiation of two distinct neoplasms in one patient.