MSK EXAM MASTER 2022(CORRECTLY ANSWERED);250 QUESTIONS AND ANSWERS

Simple cyst of the bone is seen mainly in the proximal humerus and proximal femur in children. The patients generally present with a pathological fracture. X-ray shows a lucent defect situated centrally that extends up to the epiphyseal plate. Bone involved is not expanded. Grossly, the cyst has a thin fibrous wall and it is filled with clear yellow fluid. Microscopically, the cyst wall is thin, fibrous, septa, with occasional giant cells. A peculiar calcified matrix like cementum may be present. Treatment is by aspiration of the cyst followed by injection of methylprednisolone acetate. If this fails, then surgery is advised. An aneurysmal bone cyst is a non-neoplastic locally aggressive lesion of the bone typically seen in first 2 decades of life. There is a slight female preponderance for developing them. It involves the metaphyses of the long bones. X-ray shows characteristic purely lytic lesion involving the metaphyses of a long bone