Patient with composite haemangioendothelioma containing angiosarcoma-like areas in the setting of congenital lymphoedema mimicking Stewart-Treves syndrome: a case report.

Composite haemangioendothelioma represents a rare malignant vascular tumour, with significantly more favourable biological behaviour than angiosarcoma, even in cases where angiosarcoma-like areas are present. For that reason, composite haemangioendothelioma can be easily misdiagnosed as true angiosarcoma. The rarity of this disease unfortunately hampers the development of clinical practice guidelines and the implementation of treatment recommendations. Most of the patients with localized tumour are treated by wide surgical resection, without neo- or adjuvant radiotherapy or chemotherapy. However, in the case of this diagnosis, the watch-and-wait approach is better than mutilating procedure, highlighting the necessity of establishing of the correct diagnosis.