Presentation
Complaining of symptoms similar to tarsal tunnel syndrome, to exclude nerve compression.
Patient Data
There is a well-defined mass in the posteromedial aspect of the ankle just posterior to the flexor hallucis longus tendon. This lesion measures 33 x 17 x 38 mm and it appears hypointense on T1 and hyperintense on T2 and STIR images. It is causing marked compression on the flexor hallucis longus tendon. This lesion is arising from the posterior tibial nerve with high signal intensity of lateral and medial branches of the posterior tibial nerve.
Features are consistent posterior tibial nerve sheath tumor (likely schwannoma )
Case Discussion
Schwannoma is a tumor of the tissue that covers nerves known as the nerve sheath, it develops from schwann cells. When it arises from the posterior tibial nerve, it may cause symptoms similar to tarsal tunnel syndrome.