Hypoechoic mass superficial to extensor tendon

Case submitted by John Tassone, DPM, FACPM

52-year-old female patient with a 6-month history of sub 5th metatarsal pain. No history of trauma. The pain is 4/10 when it is present. Pain is worse with standing or ambulating for long periods of time. No swelling. Pain is described as pressure and aching. Patient is not diabetic and, other than hypothyroidism (controlled), she is healthy. Clinical exam was unremarkable except for mild tenderness sub 5th metatarsal. No swelling and overlying skin was normal. No pain with DF or PF of the digit. Radiographs were unremarkable.

Ultrasound plantar 5th MPJ revealed hypoechoic mass superficial to extensor tendon to the 5th digit. This was best appreciated on the short axis. This mass was only partially compressible and was clearly a mass. Increased fluid in the tendon, such as tenosynovitis, would not be so well encapsulated as this was. (G = ganglion, E = FDL tendon, M = metatarsal head)