Intermediate nerve schwannoma: a rare tumour.

The intermediate nerve (IN), also called the nerve of Wrisberg, is a relatively small nerve with a variable anatomical course. Currently, this nerve is not addressed well in the pertinent literature. Pre-operative diagnosis of IN tumours is clinically challenging due to the lack of related symptoms. Symptoms are typically caused by the functional deterioration of neighbouring anatomical structures. In this report, we describe a patient with a schwannoma that arose at the porus acusticus of the internal auditory canal; during surgery, this proved to originate from the IN. We discuss our findings in the context of previously reported cases of IN schwannomas and analyse the vague characteristics and symptoms of this rare tumour.