Malignant schwannoma—Clinical characteristics, survival, and response to therapy

TLDR

The study reviewed 165 cases of malignant schwannoma. Among these patients, 40% had neurofibromatosis, which was linked to younger age, centrally located tumors, a 23 % five‑year survival versus 47 % for solitary tumors, distinct histology, a tendency toward multiple local recurrences (especially ominous in neurofibromatosis), poor chemotherapy response but encouraging adjuvant therapy, and a 8.5 % incidence of radiation‑related tumors that died a median of 14 months after diagnosis, underscoring the need to consider malignant schwannoma in previously irradiated sites.

Abstract

One hundred and sixty-five cases of malignant schwannoma were reviewed. Sixty-five (40%) of the patients had evidence of disseminated neurofibromatosis. Patients with neurofibromatosis were younger, had malignant schwannomas that were centrally rather than peripherally located, and had a shorter five-year survival (23%) than patients with solitary malignant schwannomas (47%). Histologically, tumors developing in patients with neurofibromatosis had a collagenous appearance, while tumors in patients without neurofibromatosis were undifferentiated and highly cellular. The clinical course of both groups of patients tended to be that of multiple local recurrences, although local recurrence had a more ominous prognosis in patients with neurofibromatosis. Chemotherapy responses in all these patients were extremely poor; however, the results of adjuvant therapy after surgery appeared encouraging. Fourteen patients (8.5%) had a malignant schwannoma in an area of prior radiation therapy and died of disease a median of 14 months after diagnosis. Malignant schwannoma should be considered in the differential diagnosis of tumors developing in areas previously treated with radiation.