Accessory soleus muscle: a review of the literature and case report.

The accessory soleus is a rare anatomic variant that must be considered in the differential diagnosis of all posteromedial soft tissue masses of the ankle. The authors review and discuss the pertinent findings of the previously reported 70 cases of accessory soleus muscles cited in English literature. A case report is presented that highlights the diagnosis of the accessory soleus muscle with magnetic resonance imaging studies and surgical excision of the mass in a symptomatic patient.