Endovascular papillary angioendothelioma in the spleen.

Endovascular papillary angioendothelioma is a rare vascular neoplasm originally described as involving the skin and subcutaneous tissues. No case has been reported to involve the spleen, although structurally similar splenic neoplasms have been reported under different names. A 5-year-old boy presented with isolated splenomegaly and was found to have endovascular papillary angioendothelioma of the spleen. Studies supported the suggestion that the endovascular papillary angioendothelioma manifests focal "high" endothelial differentiation.