Subperiosteal hemorrhage and cyst formation in neurofibromatosis: a case report.

A 7-year-old girl was disabled by neurofibromatosis complicated by leg hypertrophy, recurrent massive hemorrhage, and cyst formation in her right tibia. A grotesque deformity resulted in the right lower leg over a three-year period despite elevation, compression, and aspiration for various bleeding episodes. Massive areas of bone had to be resected on two separate occasions. The extreme vascularity of the region caused postoperative recurrences, but there was always some improvement. The pathologic findings consisted of true schwannomas in the periosteum. The basic problem of neurofibromatosis was the endoneural cell proliferation that was responsible for the hypertrophy, hemorrhages, and cyst formation. While there are various hemorrhagic problems in neurofibromatosis, this case demonstrates the characteristic massive hemorrhage and rapid new bone formation that follow minimal trauma, and illustrated the difficulties that are encountered in both nonoperative and operative management.