Kaposiform hemangioendothelioma involving the neck

Kaposiform hemangioendothelioma is a rare locally aggressive vascular neoplasm of infancy and childhood. An 18-month-old Chinese infant with a rapidly enlarging mass in the neck was presented here. Physical examination revealed a dark-red, firm mass measuring 7.0 × 4.5 cm in the anterior neck. No associated with KMS was observed despite its size. Morphologically, the tumor consisted of dense spindle cells with a nodular growth pattern, with hypocellular areas of hyalinized fibrous stroma. Immunohistochemically, both spindle and epithelioid were immunoreactive to CD34, CD31 and UEA-1, while negative to GLUT1, EMA, cytokeratin or S-100 protein. The well-formed capillaries and mature vessels but not spindle tumor cell showed reactivity for FVIII-Rag. α-SMA were detected in pericysts surrounding spindle cells. Large vessels in the tumor were positive for VEGFR3. Recurrence occurred 6 month after first operation. Wide resection was performed a second time, the patient was still alive during the 7-year follow-up period.