Case report of a young girl with Fibrous dysplasia (FD) concomitant with secondary Aneurysmal bone cyst (ABC).

Background: Fibrous dysplasia (F.D.) is a developmental bone disorder in which normal matrix of bone is replaced by fibrous tissue. Most common bones effected are ribs, long bones and pelvis. A benign type of bone lesion known as Aneurysmal bone cyst (ABC). Common bones affected by ABC are tibia and femur. Concomitant Fibrous dysplasia with secondary ABC is long bones is very rare. Case Report: We are presenting a case report of 22 years old girl, who presented to our outpatient department with complain of pain right thigh and leg. Work up was done and based on radiological findings she was diagnosed with Fibrous dysplasia (F.D). Surgery was planned for curettage and bone grafting. Per op there was blood filled sinus and fibrous septa, Biopsy was sent, it turned out to be fibrous dysplasia concomitant with secondary ABC. Discussion: Concomitant FD with Secondary ABC is very rare. After through literature review, we could identify two cases of concomitants FD with ABC in long bones. So, it was a rare case presentation.