Chondroblastoma of the talus

WellA well-defined lucent lesion with smooth margin and thin sclerotic rim at the head of the right talus. No internal calcified matrix. The lesion is less conspicuous on the lateral and oblique views.

No No other abnormality significant identified. 

Differential diagnostic considerationconsiderations would include giant cell tumortumour, osteomyelitis and chondroblastoma. Further characterization with MRI is recommended.

Well-circumscribed 24 x 14 x 16 mm ovoid lesion in the anterior inferior aspect of the right talus. The lesion is hyperintense on the fluid-related sequences, iso- to slightly hyperintense on T1. The lesion touches the inferior and anterior subarticular cortex of the talus. Although the lesion is spontaneously hyperintense on pre-contrast T1-Fat sat, there is moderate enchancementenhancement post-contrast injection. 

Extensive bone marrow edemaoedema at  andand around the talus. 

No cortical break or associated pathological fracture. 

The radiographic features of the lesion are consistent with a chondroblastoma. 

Tissue analysis of two right talar specimens from bone curettages confirms the diagnosis of chondroblastoma. 

At the time of publishing, a quick google survey of the literature demonstrates only one reported case study of a talar chondroblastoma.