1006 - Case Report: Spinal Osteoid Osteoma Mimicking Post-Traumatic Back Pain in an Adolescent

Friday, February 20, 2026

5:00 PM - 6:30 PM AST

Presenting Author(s)

SP

Sebastian Penalosa, BA

Medical Student
University of California, San Francisco
San Francisco, California, United States

Co-Author(s)

PM

Paolo Mimbella, MD

Clinical Assistant Professor
UCSF
San Francisco, California, United States

Submitter(s)

SP

Sebastian Penalosa, BA

University of California, San Francisco
San Francisco, California, United States

Case Diagnosis: Spinal osteoid osteoma presenting as persistent post-traumatic low back pain in an adolescent.

Case Description: An 18-year-old previously healthy male presented with severe lower back pain following a trampoline-related fall. Initially presumed to be a lumbar strain, his symptoms persisted despite rest and NSAIDs. Over six weeks, he developed progressively worsening nocturnal pain that was consistently relieved by NSAIDs. Initial lumbar MRI was unrevealing, with one lesion misinterpreted as a hemangioma. A subsequent sacral MRI revealed a small lesion in the posterior elements of L5, prompting further evaluation. Non-contrast CT demonstrated a 6 mm radiolucent nidus with central mineralization and surrounding sclerosis within the left L5 pedicle, confirming osteoid osteoma. Biopsy was deferred given the classic imaging features and clinical presentation. The patient was managed conservatively with meloxicam and referred for physical therapy, with radiofrequency ablation reserved for refractory symptoms.

Discussions: Osteoid osteoma is a benign osteogenic tumor representing 10–12% of benign bone tumors. While typically involving long bones, 10% occur in the spine, most often in the posterior elements. Spinal lesions are diagnostically challenging due to overlap with mechanical or post-traumatic pain syndromes. The hallmark triad of focal pain, nocturnal exacerbation, and prompt relief with NSAIDs is highly suggestive, but MRI frequently misses the nidus in spinal cases. CT remains the gold standard for diagnosis. Recognition is crucial to avoid unnecessary delays, interventions, or misattribution of pain to trauma-related etiologies.

Conclusions:

This case highlights how spinal osteoid osteoma can mimic post-traumatic back pain and underscores the importance of considering tumor etiologies in adolescents with persistent focal pain. Clinicians should recognize the characteristic pain pattern and pursue CT when MRI is inconclusive. Early identification allows for appropriate conservative management and timely referral for minimally invasive intervention if symptoms persist.