# Pulmonary epithelioid haemangioendothelioma: A comprehensive review of clinical and molecular advances

## TL;DR

This paper reviews a rare lung tumor called pulmonary epithelioid haemangioendothelioma, focusing on its clinical features, diagnosis, and treatment options.

## Contribution

The paper provides a comprehensive review of clinical and molecular advances in diagnosing and treating pulmonary epithelioid haemangioendothelioma.

## Key findings

- Histological features include spindle-shaped cells with vacuolated cytoplasm and strong positivity for CD31, CD34, and ERG.
- Surgical resection is preferred for localized lesions, while anti-angiogenic therapy and chemotherapy are used for advanced cases.
- Genetic biomarkers like WWTR1-CAMTA1 are present in most patients, and male sex and age ≥ 55 years are linked to worse outcomes.

## Abstract

•This is a rare low-to-moderate grade malignant tumor derived from vascular tissue.•The tumor can present as bilateral multiple nodules or as a single cystic lesion.•The histological features include spindle-shaped cells with vacuolated cytoplasm.•The immunohistochemical markers CD31, CD34, and ERG are strongly positive.•Surgical resection is performed for localized lesions, while anti-angiogenic therapy and chemotherapy are used for advanced metastatic lesions.

This is a rare low-to-moderate grade malignant tumor derived from vascular tissue.

The tumor can present as bilateral multiple nodules or as a single cystic lesion.

The histological features include spindle-shaped cells with vacuolated cytoplasm.

The immunohistochemical markers CD31, CD34, and ERG are strongly positive.

Surgical resection is performed for localized lesions, while anti-angiogenic therapy and chemotherapy are used for advanced metastatic lesions.

Pulmonary Epithelioid Haemangioendothelioma (PEH) is a rare vascular tumor with specific clinical symptoms (e.g., cough, chest pain) and imaging manifestations (multiple nodules in both lungs) that can be easily misdiagnosed or lead to a poor prognosis.

To systematically analyse the pathological features, diagnostic challenges, and therapeutic strategies of PEH to provide evidence for its clinical management.

Diagnostic basis: Histologically, spindle cells, cytoplasmic vacuolation and vasculogenic characteristics. Immunochemically, strong positivity for CD31, CD34, and ERG supports an endothelial origin. The genetic biomarker WWTR1-CAMTA1 is present in most patients. The treatment strategy for patients is as follows: surgery is the preferred option for localized lesions (5-year survival rate > 80 %); antiangiogenic agents or chemotherapy can be used for those with multiorgan involvement, but the efficacy is limited. Prognostic risk factors included multiorgan metastasis, male sex, and age ≥ 55 years.

Precision treatment exploring targeted gene fusions (e.g., WWTR1-CAMTA1, YAP1-TFE3); research on the effects of Bartonella infection and EGFR overexpression on tumor progression; and the development of early diagnostic models based on radiomics.