Patient History
45 F with firm immobile mass in tarsal tunnel region and pain x 3yr. On palpation pain radiating to foot and heel.
Findings
ARTICULATIONS:
Bone: Patchy heterogeneous feathery osteoedema throughout the distal tibial epiphysis and physis, talus and calcaneus.
Tibiotalar joint: No osteochondral defects or arthropathy.
Midfoot: Advanced osteoarthrosis and penetrating chondromalacia of the dorsal talonavicular joint.
LIGAMENTS:
Anterior inferior tibiofibular ligament: Intact.
Posterior inferior tibiofibular ligament: Intact.
Interosseous membrane and ligament: Intact.
Anterior talofibular ligament: Intact.
Posterior talofibular ligament: Intact.
Calcaneofibular ligament: Intact.
Deltoid ligament complex: Scarred without acute injuries.
TENDONS:
Peroneus Longus/Brevis: Intact.
Posterior Tibialis: Intact.
Flexor Compartment: Intact.
Extensor Compartment: Intact.
Achilles tendon: Mild insertional tendinosis with traction enthesopathy and nominal retrocalcaneal bursitis.
GENERAL:
Muscles: No traumatic muscle injury. No volumetric muscle atrophy.
Soft Tissue: Well-circumscribed oval-shaped low T1 with corresponding increased T2 signal homogeneously enhancing soft tissue mass measuring 1.4 cm x 1.4 cm x 2.1 cm (AP, transverse and CC) located within the tarsal tunnel anteriorly displacing the flexor tendons and posterior tibial artery.
Plantar Fascia: Mild thickening of the flexor digitorum brevis with small traction enthesophyte formation. No inflammation, tears or heel fat pad edema.
Joint Effusion: Small tibiotalar and posterior tibiotalar joint effusions, likely reactive.
Intra-Articular/Loose Bodies: None.
Impressions
1. A 1.4 cm x 1.4 cm x 2.1 cm homogeneously enhancing oval-shaped mass located within the tarsal tunnel anteriorly displacing the flexor tendons and posterior tibial artery favoring a nerve sheath tumor such as schwannoma or neurofibroma.
2. Patchy heterogeneous feathery osteoedema throughout the distal tibial epiphysis and physis, and hindfoot raising suspicion for complex regional pain syndrome type 2 (causalgia).
3. Small tibiotalar and posterior tibiotalar joint effusions, likely reactive.
4. Superomedial calcaneal haglund deformity and achilles insertional tendinopathy with traction spur.
