Atraumatic Ankle Pain Misdiagnosed As Anxiety In Nonathlete College Student

Abstract

HISTORY: 19 y/o woman with nine months of burning right ankle pain. Saw PCP after four months of pain with bland exam, pain felt to be a component of her anxiety and increased activity recommended. At five-month mark she sprained her left ankle; home physical therapy plan from student health sports clinic improved left ankle pain and worsened right ankle pain. When right ankle pain began to limit walking she returned to student health, where x-rays were normal and an ultrasound showed a 2.5 cm x 0.5 cm complex hypoechogenic mass with thickened lining consistent with a ganglion cyst. She was referred to our clinic for a sports medicine evaluation and MRI. She initially saw a non-sports physician who ordered the MRI but also felt that her anxiety was the main driver of her symptoms. On seeing the sports medicine team, her pain had evolved to burning in the right ankle limiting ambulation, standing, and sleep at night. She indicated the path of the peroneal tendons around the malleolus as the site of pain. PHYSICAL EXAM: Tearful and concerned that we would also think her anxiety was the cause of her pain. Bilateral pes planus. Skin was warm and well perfused without lesions, redness, or ecchymoses. There was fullness and tenderness to palpation to her right sinus tarsi, and pain there with passive eversion of the ankle. There was no pain over peroneal tendons with ambulation, palpation, or resisted ROM. 5/5 strength without pain to dorsiflexion, plantarflexion, eversion, and inversion. DIFFERENTIAL DIAGNOSIS: 1) Sinus Tarsi Syndrome 2) Peroneal tendinopathy3) Ganglion Cyst 4) Pigmented Villonodular Synovitis (PVNS)TESTS & RESULTS: MRI R Ankle/hindfoot w/wo contrast: Intra-articular, well-defined enhancing mass lateral to the talus measuring 3.7 x 2.9 x 2.9 cm, extends into and obliterates the sinus tarsi without surrounding soft tissue or bone marrow edema. No erosions.No other abnormality. Leading differential consideration includes PVNS, FINAL/WORKING DIAGNOSIS: Pigmented Villonodular Synovitis TREATMENT & OUTCOMES:1)Biopsy confirmed tenosynovial giant cell tumor, diffuse type (PVNS). 2)Tumor resected by ortho-oncology, final pathology: 4.3 cm diffuse-type tenosynovial giant cell tumor (PVNS). 3)At five months post-op pain and activity tolerance much improved.