[Vascular tumors of the skin and soft tissue. Overview of newly characterized entities and variants].

This review summarizes vascular tumours of skin and soft tissues that have been characterised in recent years. Although most of them are very rare, knowledge about their reproducible clinicopathological features is important to avoid diagnostic pitfalls. These lesions include: bacillary angiomatosis, a vasoproliferative, pseudoneoplastic infection of immunocompromised patients caused by Rochalimaea henselae; tufted angioma, a variant of lobular capillary haemangioma characterised by a "cannon-ball" distribution of multiple lobules composed of packed capillaries and pericytes; microvenular haemangioma, a cutaneous haemangioma composed of thin-walled and irregularly branching blood vessels which dissect dermal collagen; sinusoidal haemangioma, a distinctive variant of cavernous haemangioma which may be located in the subcutaneous breast tissue and then may be confused with well-differentiated angiosarcoma; "hobnail haemangioma" (targetoid haemosiderotic haemangioma), a benign vascular tumour with a distinctive clinical targetoid appearance and a hobnail cytomorphology of the prominent endothelial tumour cells; retiform haemangioendothelioma, a very recently characterised low-grade angiosarcoma occurring most commonly in the extremities of adolescents which is characterised by arborising blood vessels arranged in a retiform pattern and lined by hobnail-like prominent endothelial cells; Kaposi-like infantile haemangioendothelioma, a borderline malignant tumour of infants mimicking Kaposi's sarcoma histologically; epithelioid angiosarcoma, a highly aggressive tumour in the spectrum of epithelioid vascular lesions which stains positively for endothelial and epithelial immunohistological markers; benign lymph-angioendothelioma (progressive lymphangioma), a benign, slowly growing macule or plaque which has to be distinguished from well-differentiated angiosarcoma and Kaposi's sarcoma; and lymphangiomatosis of the limbs, a poorly recognised angiomatosis occurring in young patients and limited mainly to the limbs with a favourable prognosis.