Angiomatous involvement of an extremity. A spectrum of syndromes.

Congenital diffuse hemangiomatous involvement of the entire left thigh and knee joint in a 12-year-old girl was complicated by a Kasabach-Merrit type of consumptive coagulopathy. Repeated pathologic fractures of the left femur resulted in a nonunion. She also had a progressively increasing leg-length discrepancy, a stiff contracted knee, and leg atrophy distal to the knee. She was misdiagnosed originally as a Klippel-Trenauney syndrome, the progress of which is usually self-limited progression and involution. Despite steroid treatment, femoral artery banding, and intramedullary fixation of her femur, the hemangioma caused progressive debilitation of her left lower limb. At age nine, nonunion progressed to marked osteolysis and was treated by a through-knee amputation. A review of the literature revealed much confusion about multiple syndromes associated with angiomatous involvement of the lower limb. Prognostically, the depth and extent of the lesion were the most significant characteristics. This is well illustrated in this long-term follow-up study showing diffuse deep involvement that led to eventual amputation. Furthermore, this patient presents a multitude of complications developing from large angiomas.