Transformation of vestibular schwannomas into malignant peripheral sheath tumors: a systematic review and pooled analysis of patient characteristics and survival outcomes.

Twenty-one studies comprised 24 patients (7 male) with MPNSTs (median age 52 years; 8% with neurofibromatosis 2-related schwannomatosis).

All patients underwent resection after their tumors transformed into malignant peripheral nerve sheath tumor; 42% received adjuvant radiation-based therapy.

Age at diagnosis, sex, tumor size, tumor laterality, p53 status, and hydrocephalus occurrence were not associated with a statistically significant difference in overall survival.

Recurrence or progression occurred in 60% of evaluable patients.