Introduction: Osteoid osteoma is a benign bone tumor. It occurs in epiphyseal and metaphyseal regions of long tubular bones of extremities. Around 10% of osteoid osteomas present in spine. In the spine, 2% of cases involve sacrum. Here, we present an atypical case of osteoid osteoma in the sacrum. Case Report: A 15-year-old boy presented with complaints of low back pain with a 1-year duration, radiating to the left thigh.

MRI and CT-scan were suggestive of osteoid osteoma at S1-S2. Pre-operative localization of the tumor was done under CT-guidance under local anesthesia with three spinal localized osteoid osteoma was marked with methylene blue. Dissection of complete osteoid osteoma was done, along with sclerotic margin and sent for histopathological examination which was conformed osteoid osteoma. Post-operative CT-scan showed complete removal of osteoid osteoma. At 1-year follow-up,…