# Clinical and pathological analysis of pulmonary epithelioid vascular endothelial tumor

## TL;DR

This paper discusses the challenges in diagnosing a rare lung tumor called PEHE through two clinical cases and highlights the importance of accurate histopathological and immunohistochemical analysis.

## Contribution

The paper contributes by presenting two diagnostic cases of PEHE and emphasizing the need for improved awareness and diagnostic approaches among clinicians and pathologists.

## Key findings

- PEHE is often misdiagnosed as metastatic or other malignant tumors due to nonspecific clinical and imaging features.
- Accurate diagnosis of PEHE relies on histopathological morphology and immunohistochemical markers like CD34, CD31, and ERG.
- The paper highlights the importance of molecular genetic testing and comprehensive literature review in confirming PEHE diagnosis.

## Abstract

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.