Osteoid osteoma of the distal tibia

120 views525y Female10/9/2026

Clinical Presentation

Pain in the distal tibia

1Initial radiograph shows well-defined subcentimeter lytic bone lesion in the distal tibia metaphysis (see annotated images below)
2Though subtle and initially uncommented upon, there is smooth periosteal and cortical thickening of the posterior tibial metaphysis noted on the lateral images
3On the zoomed frontal images, the lytic lesion is highlighted in green
4On the zoomed lateral images, the periosteal and cortical thickening are highlighted in green (compare with the normal cortex in blue which tapers in thickness from diaphysis to epiphysis.) Selected images from an ankle MRI show a heterogenous, enhancing, cortically-based lesion in the posterolateral distal tibial metaphysis
5There is adjacent bony sclerosis as suggested by hyposignal in the medullary cavity on T1WI pre-contrast images
6There is enhancement in the adjacent bone, periosteum (which is smoothly thickened) and even soft tissues
7Osteoid osteoma is the most likely diagnosis, but CT can help better delineate a nidus
8CT roughly 9 mth after initial XRCT confirms an approximately 5 mm lytic nidus with central punctate calcification surrounded by sclerotic trabecular, cortical and periosteal reaction
93D reconstructions depict the undulated, smooth periosteal thickening.Incidentally, posteromedially to this lesion, there is a sclerotic focus of bone most likely representing an enostosis (bone island).