Các tổn thương xương radiologically mờ và histopathologically bao gồm của enchondromas. Quan trọng hàng đầu là nguy cơ của biến đổi ác tính của enchondromas vào chondrosarcomas, xảy ra trong khoảng 15% số bệnh nhân | 54 Sangueza and Requena Pathology of Vascular Skin Lesions Fig. 16. A Dramatic upper limb deformity with large venous malformations involving the entire right upper extremity in a patient with Maffuci s syndrome. B Close-up view of the lesions of the forearm. The bone lesions are radiologically translucent and histopathologically consist of enchon-dromas. Of prime importance is the risk of malignant transformation of the enchondromas into chondrosarcomas which occur in approximately 15 of the patients 21 . Other cutaneous lesions described in patients with Maffucci s syndrome include café-au-lait macules 22 and cystic lymphatic malformations 23 . In addition to chondro- Chapter 5 Cutaneous Vascular Malformations 55 Fig. 17. A Venous malformation involving the entire lower right extremity in a patient with Klippel-Trenaunay syndrome. B Close-up view of the lesions involving the leg. sarcoma other malignant neoplasms have been reported in patients with Maffucci s syndrome including fibrosarcoma 24 angiosarcoma 21 lymphangiosarcoma 25 osteosarcoma 22 malignant ovarian neoplasms 21 gliomas 21 adenocarcinoma of pancreas 24 and other multiple primary malignancies 21 22 24 .The differential diagnosis of Maffucci s syndrome has to be established with Ollier disease s in which there is dyschondroplasia without cutaneous vascular lesions 25 . Venous malformations are also prominent in and are the main cutaneous manifestation of Klippel-Trenaunay syndrome. The dominant features of this syndrome include cutaneous capillary and venous malformations congenital varicose veins and hypertrophy of the involved limb 26 Fig. 17 . When in addition to the aforementioned features there is an arteriovenous fistula the disorder is termed Parkes Weber syndrome 27 . Klippel-Trenaunay syndrome affects males and females equally. Most commonly the malformation is unilateral and the lower limb is the most commonly involved area. However in rare cases the upper and lower limbs or the upper limb .
