Osteoid Osteoma Can Occur at the Pars Interarticularis of the Lumbar Spine, Leading to Misdiagnosis of Lumbar Spondylolysis

• Published in: The American journal of case reports 2018-02, Vol.19, p.207-213
• Main Authors: Ono, Teruaki, Sakamoto, Akio, Jono, Osamu, Shimizu, Atsushi
• Format: Article
• Language: English
• Subjects: Adolescent; Bone Neoplasms - diagnosis; Bone Neoplasms - diagnostic imaging; Bone Neoplasms - surgery; Diagnosis, Differential; Diagnostic Errors; Humans; Low Back Pain - diagnosis; Low Back Pain - etiology; Lumbar Vertebrae - diagnostic imaging; Lumbar Vertebrae - pathology; Magnetic Resonance Imaging - methods; Male; Multidetector Computed Tomography - methods; Orthopedic Procedures - methods; Osteoma, Osteoid - diagnosis; Osteoma, Osteoid - diagnostic imaging; Osteoma, Osteoid - surgery; Risk Assessment; Spinal Neoplasms - diagnosis; Spinal Neoplasms - diagnostic imaging; Spinal Neoplasms - surgery; Spondylosis - diagnosis; Spondylosis - diagnostic imaging; Spondylosis - surgery; Treatment Outcome
• ISSN: 1941-5923; 1941-5923
• DOI: 10.12659/AJCR.907438

BACKGROUND Osteoid osteomas are benign bone-forming tumors characterized by local inflammation and pain. They are also characterized by a small osteolytic lesion (nidus). Spondylolysis is a defect of the pars interarticularis, which may lead to stress fractures, and is a common cause of low back pain in adolescence. Osteoid osteoma occurs predominantly in the posterior elements of the spine. Magnetic resonance imaging (MRI) signal abnormality suggesting bone marrow edema is a common finding in osteoid osteoma and early-stage spondylolysis without prominent defect. CASE REPORT An 18-year-old male was suffering from low back pain. He was diagnosed with lumbar spondylolysis on initial MRI and computed tomography (CT). Subsequent thin-slice CT demonstrated a nidus at the pars interarticularis, and variously-sliced MRI could detect widespread bone marrow edema. On the diagnosis of an osteoid osteoma, the nidus and surrounding osteosclerosis were resected. The patient's pain disappeared after surgery. CONCLUSIONS Osteoid osteoma in the pars interarticularis can be difficult to diagnosis, because MRI and CT findings for osteoid osteoma at the pars interarticularis are similar to those of the lumbar spondylolysis. The possibility of osteoid osteoma should be kept in mind when examining adolescents with low back pain.