Multinodular/Plexiform Schwannoma of the Ankle: A Case Report and Literature Review

Multinodular/plexiform schwannoma is an exceedingly rare benign peripheral nerve sheath tumor that often arises in the dermis or subcutaneous tissue, particularly of the trunk and head and neck region. The ankle is an uncommon location for this peculiar condition.

A 50-year-old man without neurofibromatosis presented with a 10-year history of a slowly growing, occasionally painful mass in the medial aspect of the right ankle. Physical examination revealed a 5-cm, elastic-soft, poorly mobile, non-tender mass. Magnetic resonance imaging (MRI) showed multiple nodular lesions with intermediate signal intensity on T1-weighted sequences and heterogeneous high signal intensity on T2-weighted sequences. Contrast-enhanced MRI demonstrated strong and homogeneous enhancement. After core needle biopsy, the lesions were successfully treated by complete surgical enucleation. Histological examination confirmed the diagnosis of schwannoma consisting of predominantly Antoni A areas. The patient had no evidence of local recurrence and no aggravated neurological deficit at the latest follow-up.

This unique case provides valuable insights into the understanding and management of multinodular/plexiform schwannoma in the ankle.