Contemporary Profile of Hybrid Nerve Sheath Tumors: Clinical, Anatomical, and Imaging Characteristics

Abstract

Simple Summary Hybrid peripheral nerve sheath tumors are rare benign tumors that contain features of more than one type of nerve sheath tumor. Because most published reports focus mainly on pathology, little is known about how these tumors present clinically, where they occur, how they appear on imaging, and how they behave after surgery. In this multicenter registry study, we analyzed 55 hybrid nerve sheath tumors in 52 patients treated at four specialized neurosurgical centers in Germany and Austria. Most tumors combined features of schwannoma and neurofibroma, commonly caused pain, and were frequently located in the lower extremities. Complete surgical removal was achieved in most cases. No malignant transformation was documented during the available, predominantly short follow-up. A relevant proportion of patients had a documented or suspected underlying tumor-predisposition syndrome. These findings improve the clinical characterization of surgically treated hybrid nerve sheath tumors; however, they do not estimate population prevalence or long-term recurrence risk.