# Epithelioid haemangioendothelioma

Source: https://onco.cc/cancers/epithelioid-haemangioendothelioma/  
OnCo record `epithelioid-haemangioendothelioma` (Cancer). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Epithelioid haemangioendothelioma is a rare vascular cancer driven by a fusion gene, usually WWTR1-CAMTA1, that behaves unpredictably: some tumours sit unchanged for years while others spread quickly. Stable disease is watched, localised tumours are removed, liver-only disease can be transplanted, and mTOR blockers such as sirolimus are the most used drugs when treatment is needed.

## Summary

Epithelioid haemangioendothelioma is a malignant vascular tumour of intermediate to high grade defined by the WWTR1-CAMTA1 fusion in about nine in ten cases and the YAP1-TFE3 fusion in most of the rest; both fusions hijack the Hippo pathway effectors TAZ and YAP. It presents as single or multifocal nodules in the liver, lungs, bone or soft tissue, often with pleural or peritoneal involvement, and is frequently found incidentally. Effusions, pain and weight loss mark the aggressive phenotype, while multifocal liver and lung disease is often indolent.

Because the natural history is so variable, the first decision is whether to treat at all: asymptomatic, stable, multifocal disease is placed under active surveillance with serial imaging. Localised tumours are resected, and hepatic epithelioid haemangioendothelioma is one of the few metastatic-appearing cancers for which liver transplantation is accepted, with good long-term survival in registry series. Radiotherapy palliates bone and painful lesions.

Systemic therapy is used for progressive or symptomatic disease. Sirolimus produced disease stabilisation and some responses in an Italian Sarcoma Group series and prospective study, and mTOR inhibition is the most widely used first option; anti-angiogenic kinase inhibitors such as pazopanib and the MEK inhibitor trametinib (SARC033) have modest activity, and anthracycline-based chemotherapy is reserved for rapidly progressive disease. Patient groups such as the EHE Foundation have funded fusion-directed drug discovery, including TAZ-CAMTA1 degraders.

## Fields

- Kind: Cancer
- Last checked: 2026-09-17
- Also known as: EHE; WWTR1-CAMTA1 sarcoma; YAP1-TFE3 haemangioendothelioma
- Tags: subtype-page
- Group: sarcoma
- Burden: Roughly one case per million people a year, in adults of any age, arising in the liver, lungs, bone and soft tissue and often multifocal at diagnosis; its course ranges from years of stability to rapid progression, and no drug is approved.
- Subtypes: WWTR1-CAMTA1 epithelioid haemangioendothelioma (about 90 percent); YAP1-TFE3 epithelioid haemangioendothelioma (younger, more vasoformative); Hepatic epithelioid haemangioendothelioma (transplant candidate); Pulmonary and pleural epithelioid haemangioendothelioma (effusions, poorer outlook); Bone and soft tissue epithelioid haemangioendothelioma
- Biomarkers: WWTR1-CAMTA1 fusion (CAMTA1 immunohistochemistry); YAP1-TFE3 fusion (TFE3 immunohistochemistry); Pleural effusion, serosal involvement and pain (aggressive phenotype); Mitotic count and size (risk stratification)

## Standard of care

- Asymptomatic, stable, multifocal: Active surveillance with imaging every three to six months; treat only on progression or symptoms. ([Active surveillance](https://onco.cc/technologies/active-surveillance/), [CT (computed tomography)](https://onco.cc/technologies/ct/), [MRI](https://onco.cc/technologies/mri/))
- Localised: Complete resection; liver transplantation for unresectable liver-limited disease; radiotherapy for bone lesions. ([Limb-salvage surgery and endoprosthetic reconstruction](https://onco.cc/technologies/limb-salvage-surgery/), [Liver transplantation for cancer (Milan criteria and beyond)](https://onco.cc/technologies/liver-transplant-oncology/), [IMRT / IGRT (modern external beam)](https://onco.cc/technologies/imrt-igrt/))
- Progressive or symptomatic: Sirolimus or another mTOR inhibitor first; pazopanib or other anti-angiogenic kinase inhibitors; anthracycline chemotherapy for rapidly progressive disease. ([mTOR](https://onco.cc/targets/mtor/), [Everolimus](https://onco.cc/drugs/everolimus/), [Sirolimus protein-bound particles](https://onco.cc/drugs/sirolimus-albumin-bound/), [Pazopanib](https://onco.cc/drugs/pazopanib/), [Doxorubicin](https://onco.cc/drugs/doxorubicin/), [Paclitaxel / nab-paclitaxel](https://onco.cc/drugs/paclitaxel/))

## State of the art

- Active surveillance is standard for stable disease because many tumours do not progress for years.
- Liver transplantation offers long survival in hepatic disease despite multifocality.
- Sirolimus is the most used drug, and TAZ-CAMTA1-directed agents are in preclinical development.

## Open problems

- No approved drug and no randomised trial.
- Predicting which tumours will progress is unreliable.
- The fusion oncoprotein is a transcription factor with no direct inhibitor yet.

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Epithelioid_hemangioendothelioma
- Wikipedia: https://en.wikipedia.org/wiki/Epithelioid_hemangioendothelioma

## Connected records

- cancers: [Angiosarcoma](https://onco.cc/cancers/angiosarcoma/), [Vascular tumours (angiosarcoma, epithelioid haemangioendothelioma, kaposiform haemangioendothelioma)](https://onco.cc/cancers/vascular-tumours/)
- targets: [MEK1/2](https://onco.cc/targets/mek/), [mTOR](https://onco.cc/targets/mtor/)
- drugs: [Doxorubicin](https://onco.cc/drugs/doxorubicin/), [Everolimus](https://onco.cc/drugs/everolimus/), [Paclitaxel / nab-paclitaxel](https://onco.cc/drugs/paclitaxel/), [Pazopanib](https://onco.cc/drugs/pazopanib/), [Sirolimus protein-bound particles](https://onco.cc/drugs/sirolimus-albumin-bound/)
- technologies: [Active surveillance](https://onco.cc/technologies/active-surveillance/), [CT (computed tomography)](https://onco.cc/technologies/ct/), [IMRT / IGRT (modern external beam)](https://onco.cc/technologies/imrt-igrt/), [Limb-salvage surgery and endoprosthetic reconstruction](https://onco.cc/technologies/limb-salvage-surgery/), [Liver transplantation for cancer (Milan criteria and beyond)](https://onco.cc/technologies/liver-transplant-oncology/), [MRI](https://onco.cc/technologies/mri/)

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