Coexistence of Ipsilateral Sacroiliitis and Simple Cyst in the Iliac Bone: A Case Report

Here, a 36-year-old female patient with inflammatory sacroiliitis and simple bone cyst of the ipsilateral iliac bone is presented. Simple bone cysts occur in the developing skeleton, usually asymptomatic; however, they are benign lytic bone lesions that can cause pathological fractures. The prevalence of simple bone cysts in the whole body has been reported as 0.30/100000. Only 2% of these rare cysts are found in the pelvis, and according to our knowledge, it is the first case in which iliac simple bone cyst is seen together with sacroiliitis on the same side.