Coexistence of osteopoikilosis and ankylosing spondylitis: A case report and review of the literature

Osteopoikilosis is a rare, benign, autosomal dominant sclerosing bone dysplasia. It is usually asymptomatic and is often detected incidentally. In some cases, it may coexist with rheumatologic diseases. Only a limited number of cases describing the coexistence of osteopoikilosis and ankylosing spondylitis have been reported in the literature. In this report, we present the case of a 58-year-old male patient who was diagnosed with both osteopoikilosis and ankylosing spondylitis. The patient presented with complaints of neck pain. Pelvic radiography revealed sacroiliitis and multiple small round osteosclerotic lesions. Based on the radiographic findings and magnetic resonance imaging, the patient was diagnosed with osteopoikilosis and ankylosing spondylitis. Nonsteroidal anti-inflammatory drugs were initiated, and adalimumab was subsequently started due to insufficient response. The patient showed significant clinical improvement. Recognition of osteopoikilosis is important in the differential diagnosis because it may mimic osteoblastic bone metastases.