MRI
Axial T1
Axial T2
Coronal T1
Axial T2 fat sat
Coronal T2 fat sat
Coronal T1 fat sat
Coronal T1 C+ fat sat
Coronal Subtraction images
An irregularly-shaped soft tissue lesion in the dorsal aspect of the big toe, immediately under the nail bed. Cortical irregularity and subcortical mild reactive bone marrow oedema in the dorsal aspect of the distal phalanx which shows enhancement, indicating the involvement of the distal phalanx by the lesion. The extensor tendon attachment at the base of the distal phalanx is likely involved.
The interphalangeal joint of the big toe seems not to be involved. The proximal phalanx is clear. The flexor tendon attachment is not definitely involved.
These changes are consistent with the known acral lentiginous melanoma.