Auckland Sarcoma Unit Experience of Epithelioid Haemangioendothelioma

Epithelioid haemangioendothelioma (EHE) is a rare vascular sarcoma of endothelial origin, characterized by heterogeneous clinical presentations with limited consensus on optimal management. This study aims to describe the incidence, clinical features, treatment, and outcomes of EHE within the Auckland regional sarcoma unit.

A retrospective review was conducted of 20 patients diagnosed with histological confirmed EHE between 1999 and 2025, managed by the Auckland Sarcoma Unit, which receives referrals across the North Island of New Zealand. Data was extracted from electronic medical records, and incomplete records were excluded. Variables analyzed included incidence, demographics, tumor location, metastatic patterns, treatment modalities, and mortality.

Twenty cases of EHE were identified in the North Island of New Zealand (1999-2025), yielding an estimated annual incidence of 0.19 per 1,000,000. The mean age at diagnosis was 57 years, with 65% female. The lower limb (50%) and liver (20%) were the most common primary sites; bony primaries accounted for 20% of cases. 50% of patients presented with metastatic disease. Metastases occurred predominantly in the lungs (60%), liver (30%), and bones (15%). Surgical resection was the main treatment for localized disease (82%), while metastatic cases were most often managed with active surveillance (56%). No patients received systemic chemotherapy. Recurrence occurred in three patients who presented with primary disease (27%). Overall mortality was 45%, higher in patients with metastasis at diagnosis (70% vs. 22%). Cumulative mortality at 1, 3, and 5 years was 15%, 25%, and 35%, respectively.

This is the largest reported case series of EHE in New Zealand, highlighting its rarity, variable clinical course, and poor prognosis. The findings underscore the need for improved data collection and international collaboration to inform management strategies for EHE.