Spontaneous Regression of Kaposiform Hemangioendothelioma Without Kasabach-Merritt Phenomenon.

Kaposiform hemangioendothelioma (KHE) is an aggressive vascular tumor often complicated by Kasabach-Merritt phenomenon (KMP), typically requiring aggressive treatment. This study reports four infants with pathologically confirmed KHE without KMP who underwent spontaneous regression under conservative management. Serial MRI showed objective tumor involution over 22-28 months. No KMP or complications occurred. These findings challenge universal aggressive intervention, supporting observation for selected non-coagulopathic cases.