Aneurysmal bone Cyst

Clinical History:
• Pain left wrist. No history of trauma. 

         

Radiological Findings: 

  •  The plain film demonstrates a lytic lesion within the metaphysis and epiphysis reaching a subarticular position.

  • There is an expansion and thinning of the cortex. No cortical breach. No soft tissue mass. No identifiable matrix calcification or ossification. 

  • The MRI shows the lesion to be confined within the bony structures. 

  • There is evidence of fluid fluid levels. 

  • No soft tissue mass.

Differential Diagnosis:

Giant cell tumour. 

Aneurysmal bone cyst. 

Fibrous dysplasia. 

Principal Diagnosis: 

Aneurysmal bone cyst. 

                                                                           


                   

Additional Information: 

• This is a slightly unusual diagnosis in a 21-year-old. An aneurysmal bone cyst is usually seen before epiphyseal fusion. It reaches a subarticular position and is characterized by this. Fluid-fluid levels on MRI imaging are highly suspicious but not diagnostic of an aneurysmal bone cyst. A giant cell tumour is a good alternative diagnosis particularly in a patient of this age. Subarticular lesions in a 21-year-old would more commonly be due to giant cell tumours.