A case of kaposiform hemangioendothelioma at the sigmoid colon.

We report a case of kaposiform hemangioendothelioma (KHE) occurring at the sigmoid colon in an 8-year-old male. He had experienced lower abdominal pain and fever for several days. Contrast-enhanced CT images revealed a well-enhanced mass involving several large and small cystic parts with thin, enhanced walls at the sigmoid colon. The diagnosis was made histopathologically after surgical resection; the cystic parts corresponded to dilated lymphatic vessels. KHE is a rare, locally aggressive, vascular tumor that usually occurs in the soft tissues of the extremities. However, a case occurring in the bowel is extremely rare, and usually appears as bowel wall thickening. This is a unique case of KHE appearing as a mass-shaped hypervascular lesion in the bowel. Dilated lymphatic vessels in KHE may appear as a cystic part of the lesion.