The patient was a 35-year-old man who worked as a pipe fitter. He was referred to a physical therapist by an orthopaedic surgeon for a chief complaint of progressively worsening pain in the medial aspect of the right distal Achilles tendon and heel that began insidiously 12 months earlier, which was consistent with a diagnosis of insertional Achilles tendonitis. Prior radiographs revealed mild calcification at the insertion of the Achilles tendon. Despite physical therapist intervention for 8 weeks, the patient did not improve. Subsequent magnetic resonance imaging revealed a large multiloculated ganglion cyst in the tarsal tunnel.