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

• 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.