[Osteoblastoma of the ankle: an uncommon location]

Osteoblastoma is a rare benign bone tumor occurring in adults younger than 30 years, with a clear predominance in men. It mainly occurs at the level of the spine and of the diaphysis in long bones. It occurs exceptionally in the ankle. We here report the case of an adult patient with osteoblastoma of the left ankle revealed by localized pain and partial functional disability. Standard radiographic evaluation was normal. Given the persistence of complaints CT scan was performed, but findings resulted in a misdiagnosis of osteochondritis. Anatomo-pathological examination of the surgical specimen allowed to adjust the diagnosis. Patient' s outcome was simple with very satisfactory functional result. Our case study is important due to the uncommon age of occurrence of the disease (patient older than 30 years) and to its unusual location at the level of the ankle. Even if aggressive forms have been reported in the literature, the prognosis of osteoblastoma is good and recurrences can be avoided by adequate surgical treatment.