CASE 42
By: Dr. Mai Mattar, MD and Dr. Nizar Al-Nakshabandi MD, FRCPC
HISTORY: A 20-year-old male with night pain only relieved by NSAIDs.
What are your findings?
What is the differential diagnosis?
What are the causes?
FINDINGS:
Coronal T1 and T2FS of the tibia demonstrating edema in the medullary cavity with cortical thickening along the lateral cortex. Axial T2FS and axial non-contrast CT clearly demonstrating a small nidus within the lateral cortex of the distal tibia.
DIFFERENTIAL DIAGNOSIS:
Osteoid osteoma.
Brodie’s abscess.
Osteoblastoma.
Stress fracture.
DIAGNOSIS:
Intra-cortical osteoid osteoma.
PEARLS AND DISCUSSION:
Osteoid osteoma is a benign tumor arising from the osteoblasts and thought to be a smaller version from osteoblastoma. Usually less than one half centimeter. They can occur any part of the body but most commonly in the long bones such as the femur and tibia.
It occurs at any age but are most common between 4 and 25 years of age. Males are affected 3 more times commonly and females.
Severe pain occurs at night and may affect sleep quality. It would be associated with limping, muscle atrophy, bowing deformity, and increased or decreased bone growth.
Radiographically the findings are as discussed above.
Treatment of pain is relieved by nonsteroidal anti-inflammatory drugs.
CT-guided radiofrequency ablation has emerged as an alternative to surgical resection. This procedure is done by introduction of the radiofrequency probe into the tumor nidus through a cannulated needle under CT guidance. Heat is then applied locally to destroy the tumor cells. This technique has been shown to have equivalent safety and like surgical techniques. Newer techniques with MRI guided HIFU has been applied since 2014.
FURTHER READING:
Lateur, L.; Baert, A. L. (1977). "Localisation and diagnosis of osteoid osteoma of the carpal area by angiography". Skeletal Radiology. 2 (2): 75
Rosenthal, D I; Alexander, A; Rosenberg, A E; Springfield, D (1992-04-01). "Ablation of osteoid osteomas with a percutaneously placed electrode: a new procedure.". Radiology. 183 (1): 29–33
Weber, Marc-André; Sprengel, Simon David; Omlor, Georg W.; Lehner, Burkhard; Wiedenhöfer, Bernd; Kauczor, Hans-Ulrich; Rehnitz, Christoph (2015-04-25). "Clinical long-term outcome, technical success, and cost analysis of radiofrequency ablation for the treatment of osteoblastomas and spinal osteoid osteomas in comparison to open surgical resection". Skeletal Radiology. 44 (7): 981–993.
