Presentation
Three month history of knee and lower leg pain. No trauma. Normal bloods. No constitutional symptoms.
Patient Data
Tibial epiphyseal lucent bone lesion. There is a large lucent lesion just beneath the tibial spines with a possible smaller lesion medially.
Multi-lobulated fluid-signal lesion in the tibial epiphysis, but extending to the physis posteriorly. Associated bone edema in the metaphysis, but very little around the actual lesions.
Despite the location and lack of symptoms, infection is the most likely cause. However, a tumor is also a possibility.
Surgical biopsy and histopathological analysis was performed:
Marrow fibrosis with patchy chronic inflammatory infiltrate and granulation tissue formation. Appearances most in keeping with acute on chronic osteomyelitis, assuming this fits with the clinical presentation and radiological findings.
No evidence of atypia or malignancy.
Case Discussion
While the location of infection in this case is atypical, the lobulated fluid-signal epiphyseal/physeal lesion fit best with a Brodie's abscess, which was confirmed after surgical biopsy and curettage.