Abstract
Malignant schwannomas are uncommon sarcomas that arise from the sheath of Schwann surrounding peripheral nerve fibers. These tumors may arise spontaneously in adult patients or may occur with reportedly increased frequency in patients with neurofibromatosis Type I. The tumors have had a reputation for malignancy with rapid metastasis, especially when they arise in relation to neurofibromatosis. We have reviewed the experience of the connective tissue oncology unit with patients with these tumors during the past 25 years. There were 80 malignant schwannomas identified in 41 females and 39 males with a mean age of 36 +/- 17 years. The largest numbers of tumors were seen in the thigh, shoulder, and pelvis but they also occurred in more central (abdomen and thorax) and distal (forearm, hand and foot) locations. The Musculoskeletal Tumor Society stages showed that the majority of the patients had Stage II (high grade but not metastasized) tumors; however, additionally, 10 of the patients had metastases at outset (Stage III). Patient gender was not a factor but stage was a notable determinant of survival. Anatomic location also had a significant effect. Overall, the entire series of patients had a survival of 85% at 11 +/- 5 years and even more remarkable was the fact that there was no difference between the numbers and outcome statistics for tumors arising spontaneously and those occurring in patients with neurofibromatosis.
