Objective: providing the rarity of malignant and intermediate vascular tumours (MVTs, IVTs) in children little is known about their clinical course, optimal treatment and variables predicting survival.

Material and methods: 32 children with MIVTs (14 angiosarcomas-AS, 5 epithelioid haemangioendotheliomas-EHE and 13 IVTs), registered in Polish and German Paediatric Soft Tissue Sarcomas (STS) Study Groups, treated with CWS-81, −86, −91 and −96 protocols.

Results: AS presented with advanced disease (84%), deep-seated T2 invasive tumours (71%), > 5cm in diameter (64%). Primary excision (PE) was incomplete in all and response to CHT/RTX disappointing. Nine/14 children entered CR; however all relapsed and, except one, died of disease. EHE and IVTs presented mainly in local stages (66,7%) and tumours > 5cm (72%). Complete PE was feasible in 30% and response to CHT/IFN poor in half. 16 patients entered CR, but six relapsed and, except one, died of disease.

In multivariate analysis male gender, AS histology, tumour size > 5cm, T2 invasiveness and lack of CR after Ist line therapy were independent predictors of poorer 5-year-OS, while AS histology and T2 invasiveness – of inferior 5-year-EFS. Radicality of PE was an independent prognostic factor for survival in univariate but not multivariate analysis.

Conclusions:

Current WHO classification has placed EHE in MVTs, however it may behave similarly rather to IVTs than AS.