PIK3CA and Klippel-Trénaunay syndrome: The PIK3CA gene expresses an overactive phosphatidyl inositase, leading to “abnormal growth of bones, soft tissues, and blood vessels.”[9] In 1975, Klein and Kaplan reported bladder hemangioma in children, the first confirmed case of Klippel-Trenaunay syndrome associated with urogenital hemangioma.[10] In 1988, Campistol JM reported on a 19-year-old woman with KTS who developed severe unilateral upper urinary hematuria.