Schwannomas are rare, slow-growing, benign tumors consisting of Schwann cells. MRI is the preferred noninvasive modality for evaluating the lesion. Surgical resection with biopsy for histologic assessment can confirm the diagnosis of a Schwannoma and help rule out a malignant tumor. Referring to the study of our case and to the literature, the diagnosis is delayed for several years when the schwanomma has a location above the flexor retinaculum. The diagnosis of schwanomma must always be considered in the face of internal retromalleolar swelling of the ankle, even small or asymptomatic, radiological investigations must be requested.

A schwannoma of the tibial posterior nerve is a rare occurrence benign tumor of Schwann cells. The diagnostic has often delayed for several years. Clinical examination, MRI, and surgical resection with biopsy for histologic assessment can confirm the diagnoses and help rule out a malignant tumor.