Intraosseous schwannoma


Intraosseous schwannomas are rare, representing <1% of primary bone tumors. They tend to occur in the mandible (arising from the inferior alveolar nerve), however can occur in almost any bone, and tend to occur in or near nutrient canals.

Radiographically, intraosseous schwannomas tend to present with benign, cyst-like features, and on MR they typically show features similar to those seen here, with isointense signal to muscle on T1 and heterogeneously hyperintense T2 signal. As these characteristics are not unique, predicting this histologic entity in the differential diagnosis is difficult, however should at least be considered in appropriate cases. 

In the past, this entity has routinely been referred to as an intraosseous neurilemmoma.

Special thanks to Dr. Cristina Costales for the photomicrographs.