Non-epiphyseal chondroblastoma arising in the iliac bone, and complicated by an aneurysmal bone cyst: a case report and review of the literature.

Chondroblastoma is a benign bone tumor that typically arises in the epiphysis of a long bone. However, when it occurs in non-epiphyseal location in flat bones, it may create a diagnostic problem. We describe such a case of chondroblastoma arising in the iliac bone. A 29-year-old man was incidentally found to have a bony pelvic lesion while undergoing evaluation for Crohn's disease. The radiographs and CT revealed an expansile lytic lesion in the right iliac bone. A core biopsy of the lesion was performed. The histopathology revealed the lesion to be a chondroblastoma with secondary features of aneurysmal bone cyst. An en bloc surgical resection of the tumor was performed.