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

Accessory soleus muscle is a rare condition which presents as a soft-tissue mass medial to the calcaneum and distal Achilles tendon. Though congenital in origin, it manifests in the second and third decades of life as a soft- tissue mass due to muscle hypertrophy. Patients may be asymptomatic or pres ent with a painful ankle mass. It is important to be aware of this conditio n when interpreting CT or MRI of the ankle, which show characteristic findi ngs of a normal muscle in an abnormal location.