Synonyms

EHE

Category

Bone and soft tissue

Behaviour

Malignant

Grade

Variable

Gender

Female

Tissue of Origin

Vascular

Epidemiology

• Any age group
• Average age 50 years
• Rarely children

Clinical Features

• Asymptomatic discovery in many cases - incidental finding on imaging
• Hepatic EHE: abdominal pain, hepatomegaly, jaundice if advanced
• Pulmonary EHE: dyspnoea, cough
• Cutaneous EHE: nodules, patches, plaques
• Bone EHE: pain, pathological fracture
• Slow-growing but with potential for multifocal dissemination

Location

• 50% oft tissue EHE arise from or close to a blood vessel
• Any Bone can be affected
• Liver, lung, skin and lymph nodes also documented

Imaging

• CT chest/abdomen/pelvis - multifocal lesions common (liver, lung, Bone)
• MRI primary site - well-defined lesions with Variable enhancement
• Hepatic EHE: hypodense on CT, hypointense T1, hyperintense T2 on MRI
• Pulmonary EHE: bilateral nodules, often in Lower lobes
• Bone EHE: lytic or mixed lytic-sclerotic lesions

Pathology

• Epithelioid endothelial cells arranged in cords/nests in myxoid to Fibrous stroma
• Intracellular and extracellular haemophagocytosis
• CD31+, CD34+, ERG+, CAMTA1+ (nuclear; Highly characteristic)
• WWTR1-CAMTA1 fusion in 90%; YAP1-TFE3 in minority

Genetics

• CD31, ERG, CD34, Fli1
• Cytokeratin
• WWTR1-CAMTA1 gene fusion seen in older patients
• YAP1-TFE3 gene fusion seen in younger patients

Treatment

• Wide resection
• Chemotherapy for progressive or unresectable tumours

Prognosis

• 79% 1-year survival
• 72% 5-year survival
• 60% present with metastatic disease

Key Points

• WWTR1-CAMTA1 FISH is diagnostic - present in vast majority
• Multifocal presentation common - staging must assess all sites
• Indolent disease may be observed; intervention for progressive lesions
• Hepatic transplantation considered for localised multifocal hepatic disease
• Sirolimus, sorafenib, bevacizumab for progressive metastatic disease

Workup - Blood Tests

• FBC, U&E, LFTs - pre-operative baseline
• LFTs - hepatic EHE commonly presents with liver dysfunction
• Coagulation screen

Workup - Local Imaging

• Plain radiograph
• MRI + conrast primary site

Workup - Biopsy

• Core needle biopsy - confirm diagnosis
• Immunohistochemistry: CD31+, CD34+, ERG+, CAMTA1+ (nuclear; Highly specific)
• WWTR1-CAMTA1 FISH - present in 90% of EHE; confirms diagnosis
• YAP1-TFE3 fusion testing in CAMTA1-negative cases

Workup - Staging

• CT chest/abdomen/pelvis - multifocality common
• Liver biopsy if primarily hepatic disease

Workup - Other

• MDT review at specialist centre - active surveillance appropriate in indolent disease
• Sirolimus, sorafenib, bevacizumab for progressive disease

Follow-up Summary

• Malignant Vascular tumour (Variable grade) - Follow-up guided by site and grade
• Year 1: Post-operative visit within first 6 weeks; 3- 4-monthly clinical examination and CXR
• Year 2-4: 6-monthly clinical examination and CXR
• Years 5-10: Annual clinical examination and CXR
• Discharge at 10 years after surgery