Introduction

Unicameral bone cysts are non-neoplastic, serous, fluid-filled bone lesions most commonly found in the proximal humerus. The condition typically presents in patients less than 20 years of age with a pathologic fracture through the lesion. Diagnosis is made with radiographs showing a central, thatic, well-demarcated, metaphysia lesion with cystic expansion and a characteristic fallen leaf sign. Treatment is usually a mobilization for proximal Humerus lesions with pathologic fracture. Surgical curret and bone grafting is indicated for pathologic fractures that have a high rate of refracture and malunion.