Here, two options are there which are included in the differential diagnosis of the lytic lesion in the proximal humerus, i.e., unicameral bone cyst and aneurysmal bone cyst. We cannot differentiate between two on the basis of information provided in the question. However, the best option here is a unicameral bone cyst because : -A pathological fracture is more common in the unicameral bone cyst. In unicameral bone, cyst patient is asymptomatic and presents only after the occurrence of pathological fracture. Most common site of unicameral bone cyst is proximal humerus. A unicameral bone cyst is more common in a male child.So in this question, the best answer is a unicameral bone cyst. However, the exactly similar presentation may occur in aneurysmal bone cyst also.