Accessory soleus muscle and its clinical significance

Abstract

Accessory soleus muscle, presenting as a tumefaction in the posteromedial region of the ankle, is a rare congenital anatomical variant. In cadaveric studies, the incidence ranged from 0.7 to 6%. It manifests in the 2^nd or 3^rd decade of life with increase in the muscle mass. Symptomatic cases often present after an increase in physical activity, usually in sports persons as ankle pain and swelling. It is reported to be frequently seen associated with Achilles tendonopathies. The swelling medial to the tendocalcaneous can be due to ganglion/ lipomas/ hemangiomas/ synoviomas/ sarcomas. The condition can be diagnosed clinically by radiographic imaging, MRI being the investigation of choice. Symptomatic cases can be treated with fasciotomy or surgical excision of the mass.