Clinicopathological features of Kaposiform hemangioendothelioma.

Kaposiform hemangioendothelioma (KHE), an intermediate tumor of endothelial origin in childhood, is often associated with Kasabach-Merritt phenomenon (KMP). In this study, 22 cases of KHE were immunochemically studied for CD31, CD34, ERG, smooth muscle actin (SMA), D240, GLUT1 and Ki67. The patients (15 males and 7 females) ranged in age from 13 days to 7 years (median, 2 mo). Lesion developed on the extremities/joint (12 cases), chest/abdominal wall (6 cases), head/neck (4 cases), and presented both superficial and deep soft tissue. The superficial change was commonly enlarging cutaneous lesion with ill-defined red to purple indurated plaque. 15 of the 22 cases (68%) developed KMP, with consumptive thrombocytopenia or bleeding complications. Tumors consisted of infiltrating nodules of fascicles of spindleshaped endothelial cells and slitlike vascular channels with irregular tumor margins. On immunohistochemistry (IHC), endothelial cells were diffusely positive for CD34, CD31 and ERG but negative for GLUT1, and the peripheral area of proliferative capillaries were markedly positive for D240. Adjuvant medical therapy and sclerotherapy were prepared for the tumor and the associated KMP, and then all patients were treated by complete surgical excision. Follow-up information was available in 22 patients (8 to 26 months, mean 15 mo), and indicated that 1 died of multiple organ failure and 21 were alive without residual disease. In conclusion, our results suggest that KHE can occur in the embryonic period, and patients with KMP often have earlier onset time and larger lesional size. KHE patients given with adjuvant corticosteroids and urea injection and complete resection rarely relapse.