Synonyms

• Angiolymphoid hyperplasia with eosinophilia (ALHE)
• histiocytoid haemangioma

Category

Bone and soft tissue

Behaviour

Benign

Gender

Both equally

Tissue of Origin

Vascular

Epidemiology

• Benign Vascular tumour with epithelioid endothelial cells
• Peak incidence in young to middle-aged adults
• No significant sex predilection
• May be multifocal

Clinical Features

• Painless or mildly painful soft tissue nodule
• Skin lesions: pinkish-red papules or nodules in head/neck region
• Bone lesions often painful
• Eosinophilia (peripheral blood) in some cases

Location

• Skin and subcutaneous tissue of head and neck (cutaneous form)
• Bone: skull, femur, vertebra, hands
• Soft tissue of any location

Imaging

• Well-defined lytic Bone lesion with geographic margins
• Soft tissue: well-circumscribed Vascular mass on MRI
• Variable enhancement on CT
• May be multifocal in Bone

Pathology

• Lobular Vascular proliferation with plump epithelioid endothelial cells
• Eosinophilic inflammatory infiltrate
• CD31, CD34, FLI1 positive
• FOS or FOSB rearrangements present

Genetics

• FOS rearrangements (ZFP36-FOS, ACTB-FOS)
• FOSB rearrangements in subset
• Distinct from angiosarcoma genetically and biologically

Treatment

• Simple excision for soft tissue lesions
• Curettage for Bone lesions
• Multi-focal lesions may require systemic therapy (sirolimus, propranolol) or observation

Prognosis

• Excellent - Benign tumour
• Local recurrence possible but no Malignant transformation
• Multifocal disease well-tolerated

Key Points

• FOS rearrangements are diagnostic - distinct from epithelioid angiosarcoma
• Eosinophilia in peripheral blood and inflammatory infiltrate in tissue are characteristic
• Must be distinguished from epithelioid angiosarcoma and epithelioid haemangioendothelioma
• Simple excision is curative in most cases

Workup - Blood Tests

• FBC - may show eosinophilia
• U&E, LFTs - pre-operative baseline

Workup - Local Imaging

• Plain radiograph - if Bone involved; lytic lesion with geographic margins
• MRI - better for soft tissue characterisation
• CT - if Bone lesion; assesses cortical integrity

Workup - Biopsy

• Core needle biopsy or excision biopsy
• IHC: CD31+, CD34+, FLI1+, Desmin Variable
• FOS or FOSB rearrangements (FISH or RT-PCR) - diagnostic and distinguish from epithelioid angiosarcoma
• Histology: epithelioid endothelial cells, eosinophilic infiltrate

Workup - Staging

No staging required - Benign lesion

Follow-up Summary

Year 1: Post-operative visit within first 6 weeks, then supported discharge