Presentation
Pain and swelling of right thumb for one month
Patient Data
Axial and coronal MRI images of right thumb demonstrate well-defined T2w slightly hyperintense, PD fat-sat hyperintense and T1w isointense juxtacortical lesion along the medial (ulnar) surface of the shaft of proximal phalanx of thumb with surrounding inflammatory edema. There is saucerisation (remodeling due to pressure effect) of the underlying cortex; however, there is intact T2w hypointense cortex. Mild marrow edema is noted in the proximal phalanx.
Corresponding CT sections in bone window demonstrate lytic nature of proximal phalangeal juxtacortical lesion with faint peripheral calcifications and thinning of the underlying medial cortex. No intralesional calcifications noted.
Case Discussion
MRI of right thumb showed well-defined PDW hyperintense juxtacortical lesion along the medial surface of proximal phalanx with thinned-out and intact underlying cortex. CT sections of the lesion showed faint peripheral wall calcifications. Mild surrounding inflammatory soft tissue edema was seen. These features were suggestive of juxtacortical chondroma.
The patient underwent surgical excision of the lesion. Histopathology showed a benign lesion comprised of lobules of mature chondroid areas surrounded by sparse spindle cells and mature bony trabeculae. Histopathological features were consistent with juxtacortical (periosteal) chondroma,
Juxtacortical chondromas are benign cartilaginous tumors arising within the periosteum. It is commonly seen in young patients.