Are Osteoid Osteoma and Ankylosing Spondylitis in Some Way Linked? A Case Report

We present a 35-year-old male, who initially complained of progressive and persistent inflammatory back pain for 2 years, which was diagnosed as a T12 thoracic spine osteoid osteoma. The patient underwent intralesional resection of the tumor via a posterior approach, with immediate post-operative pain relief, and 2 years of pain-free spine interval. Recently, the patient presented with an inflammatory back pain. Visual Analogic Scale (V.A.S) was 7/10 and stiffness,The Back Pain Functional Scale (BPFS) was 30/60, suggesting a recurrence of the spinal Osteoid Osteoma (OO), diagnosis ruled out giving the negativity of the spine MRI and CT scan. Therefore, an ankylosing spondylitis was suspected, hence, sacroiliac joints MRI was performed, depicting an active bilateral sacroiliitis, confirming the diagnosis of AS according to ASAS criteria. The aim of this paper is to point out similarities between OO and AS and their clinical and probable therapeutic implications. Though few cases of their association have been reported in the literature, both of bone osteoblastic tumors and Ankylosing Spondylitis (AS) share a number of common features, which let us assuming a possible relationship and therefore, the necessity to assess for sacroiliitis in patients with osteoid osteoma. Differential diagnosis should be considered especially in patients with inflammatory back pain. Moreover, a purely pharmacological approach to the management of OO by the use of biological agents may be considered.