Intravascular papillary endothelial hyperplasia in the kidney of a child.

Intravascular papillary endothelial hyperplasia (IPEH) is a benign vascular lesion which is thought to represent an unusual form of organizing thrombus. A case of IPEH in the kidney of a 7-year-old girl is described. She suffered from intermittent flank pain and gross hematuria for 6 months. On radiological examinations, well-defined hypoechoic lesions were identified in the medullary portion of the left kidney. A well-demarcated, sponge-like mass was noted on gross examination. It was an intravascular mass lined by a fibrous capsule of various thicknesses. It was characterized by papillary fronds lined with benign endothelial cells. This is the first description of a renal IPEH in a child.