botryoid sarcoma

n.
  1. A polypoid form of rhabdomyosarcoma occurring in children, most frequently in the urogenital tract, and characterized by the formation of grapelike clusters of neoplastic tissue.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.