Clinical and pathological analysis of pulmonary epithelioid vascular endothelial tumor.

Pulmonary epithelioid hemangioendothelioma (PEHE) is a rare, low-grade malignant vascular tumor with nonspecific clinical and imaging features. Diagnosis remains challenging, particularly in intraoperative frozen sections and biopsy specimens, and relies on characteristic histopathological morphology and immunohistochemical findings, supplemented by molecular genetic testing when necessary. We report two cases of PEHE: a 72-year-old asymptomatic male with multiple pulmonary nodules detected incidentally on CT, initially diagnosed as "malignant tumor, likely metastatic" by frozen section during wedge resection but later confirmed as PEHE on paraffin pathology; and a 53-year-old female presenting with cough, sputum, dyspnea, and chest pain, whose CT showed scattered ground-glass and solid nodules, initially misdiagnosed as non-small cell carcinoma with nodal metastasis via percutaneous biopsy but ultimately confirmed as PEHE through immunohistochemistry (positive CD34/CD31/ERG). These cases underscore the diagnostic pitfalls of PEHE and aim to enhance awareness among clinicians and pathologists. A comprehensive review of current literature is also provided.