Plantar foot mass There is a mass within the plantar soft tissues of the foot beneath the first metatarsal that appears to arise of the medial band of plantar fascia. It is predominantly isointense to skeletal muscle on T1, containing scattered foci of low signal intensity, and slightly hyperintense to skeletal muscle on T2WI, which also demonstrate scattered foci of low signal intensity. There is diffuse enhancement of the mass following contrast administration and it measures 2.5 x 1 cm in the transverse dimensions and approximately 3 cm in the longitudinal dimension. This is most compatible with plantar fibromatosis. An additional tiny focus of enhancement is noted along the plantar margin of the flexor digitorum brevis muscle, which could conceivably represent an additional small focus of fibromatosis.There is nonspecific edema within the dorsal subcutaneous tissues of the foot. Mild to moderate osteoarthritis affects the first MTP and TMT joints. There is additional mild osteoarthritis of the navicular-medial cuneiform articulation. There is mild enhancement and edema along the tendon sheath of the flexor digitorum longus suggesting mild tenosynovitis.
MRI features of plantar fibromatosis with other findings described above.