Wk 4, Case 5 - Review

Patient History
46-year-old man with a history of gout, complaining of enlargement and stiffness of the right great toe.

Findings
Skeletal/osseous:
3.8 x 3.4 x 2.7 centimeter heterogenous intermediate T1 signal, T2 hypointense signal tumefactive soft tissue mass centered around the dorsal aspect of the 1st metatarsophalangeal joint, with a portion of the mass extending to the plantar aspect of the joint. Heterogenous, predominantly peripheral enhancement is noted within the mass postcontrast. Central component demonstrates mild T2 hyperintensity. Prominent/large underlying pressure- and hook-type erosions with overhanging edges are noted at the dorsal aspect of the base of the proximal phalanx and 1st metatarsal head. Further erosive change is seen at the plantar aspect of the 1st metatarsal head.
Further large erosions with overhanging edges are noted around the 3rd metatarsal base (adjacent to the metatarsophalangeal joint). A prominent juxta-articular erosion with overhanging edges is seen at the lateral aspect of the 5th metatarsal head.
Flexion deformities of the 2nd to 5th digits, consistent with claw toe deformities.
No micro- or macro-trabecular fracture.

Articulations:
Severe erosive arthropathy involving the 1st metatarsophalangeal joint as described above. Further moderate-to-marked erosive arthropathy involving the 3rd tarsometatarsal articulation and 5th metatarsophalangeal joint.

Mild midfoot arthrosis with periarticular erosions at the dorsal aspect of the medial cuneiform. Associated mild stress-related osteoedema.
Lisfranc joint:
Intact.

Tendons:
Mild focal tendinosis of the distal flexor hallucis longus tendon. Otherwise intact and unremarkable in appearance.

Ligaments:
Destruction of the 1st metatarsophalangeal joint collateral ligaments.
Plantar plates:
Intact.

Soft tissues:
Large soft tissue mass surrounding the 1st metatarsophalangeal joint as described above. Soft tissue thickening/callus formation adjacent to the 5th metatarsal head, consistent with altered biomechanics of weight-bearing.

Other:
Moderately atrophic intrinsic muscles of the forefoot.

Impressions
1. Large centrally necrotic soft tissue mass surrounding the 1st metatarsophalangeal joint, consistent with tumefactive gouty tophus (compatible with known history of gout).
2. Large osseous erosions at the 1st metatarsophalangeal joint, typical for gout.
3. Erosions of the midfoot and forefoot with overhanging edges, consistent with gout.