Primary Pulmonary Epithelioid Angiosarcoma With Partial Response to Paclitaxel Treatment: A Case Report

Figure 1. Initial chest radiograph Upright posteroanterior chest radiograph at presentation shows a large left hilar mass.

Figure 2. Radiographic findings at initial presentation (A) An axial contrast-enhanced computed tomography image (mediastinal window) demonstrates a large primary tumor in the left hilum with encasement of the pulmonary artery (orange arrow). (B) The corresponding lung window image illustrates the interface between the large tumor and the surrounding lung parenchyma. (C) Positron emission tomography-computed tomography (PET-CT) maximum intensity projection image confirms the extent of the disease, showing multiple sites of high fluorodeoxyglucose (FDG) uptake indicative of widespread metastases.

Figure 3. Histopathological examination Hematoxylin and eosin (HE) staining showing an invasive proliferation of large, atypical cells with mild pleomorphism, abundant cytoplasm, and prominent nucleoli. Some cells form irregular, primitive vascular channels containing red blood cells within their cytoplasm.

Figure 4. Immunohistochemical examination Tumor cells were positive for (A) vimentin and (B) pan-cytokeratin. The vascular endothelial markers (C) CD31 and (D) CD34 were strongly positive, confirming the endothelial origin of the tumor.

Figure 5. Treatment response Computed tomography (CT) scans (A) with contrast before treatment and (B) without contrast on day 29 of paclitaxel therapy, with partial reduction in the size of the mass.