1. MedPix Medical Image Database COW - Case of the Week Case Contributor: Omar Khan Affiliation: Childrens Hospital of Dayton, OH

2. MedPix No: 14410 - History Pt Demographics: Age = 15 y.o. Gender = boy Patient is a 15 year old Caucasian male who presented with several months of unrelenting back pain along with the development of scoliosis. Pain is reported to be worse during nighttime and no longer controlled with the use of NSAIDs. Downloaded by (-1)

3. MedPix No: 14410 - EXAM & LABS Physical exam is remarkable only for S shaped scoliosis (right thoracic curve and left lumbar curve).No abnormal laboratory findings.

4. Osteoid Osteoma Standing AP radiograph of thoracolumbar spine depicting thoracolumbar levoscoliosis with the apex at approximately T11. Downloaded by (-1)

5. Osteoid Osteoma MRI depicting mildly enhancing mass at the lamina of T11 on the right side which measures 2.7 x 1.3 x 2.0 cm. Corresponds to the apex of the levoscoliosis. Edema present in right erector spinae musculature. Downloaded by (-1)

6. Osteoid Osteoma MRI depicting mildly enhancing mass at the lamina of T11 on the right side which measures 2.7 x 1.3 x 2.0 cm. Corresponds to the apex of the levoscoliosis. Edema present in right erector spinae musculature. Downloaded by (-1)

7. Osteoid Osteoma MRI depicting mildly enhancing mass at the lamina of T11 on the right side which measures 2.7 x 1.3 x 2.0 cm. Corresponds to the apex of the levoscoliosis. Edema present in right erector spinae musculature. Downloaded by (-1)

8. Osteoid Osteoma MRI depicting mildly enhancing mass at the lamina of T11 on the right side which measures 2.7 x 1.3 x 2.0 cm. Corresponds to the apex of the levoscoliosis. Edema present in right erector spinae musculature. Downloaded by (-1)

9. Osteoid Osteoma MRI depicting mildly enhancing mass at the lamina of T11 on the right side which measures 2.7 x 1.3 x 2.0 cm. Corresponds to the apex of the levoscoliosis. Edema present in right erector spinae musculature. Downloaded by (-1)

10. Osteoid Osteoma CT of thoracic spine depicting area of abnormality at T11 vertebral body just medial to the inferior costal - facet. There is a well-defined 1 cm lytic lesion with a bony nidus which demonstrates a large amount of benign appearing sclerotic bony overgrowth in the surrounding bone. Downloaded by (-1)

11. FINDINGS Standing AP and lateral thoracolumbar spine:S-shaped thoracolumbar scoliosis. 16 degrees dextroscoliosis between T2 and T8.33 degree levoscoliosis between T9 and L2. 19 degreedextroscoliosis between L3 and L5MRI of the thoracic spine: Mildly enhancing mass at the lamina of T11 on the right side which measures 2.7 x 1.3 x 2.0 cm. Likely originating in the soft tissue anderoding into the pedicle. Corresponds to the apex of thelevoscoliosis. Edema present in right erector spinae musculature.CT of the thoracic spine:Area of abnormality on the MR is along thelamina of the T11 vertebral body just medial to the inferior costal facet. There is a well-defined 1 cm lytic lesion with a bony nidus which demonstrates a large amount of benign appearing sclerotic bonyovergrowth in the surrounding bone.

12. DIFFERENTIAL DIAGNOSIS What is your Differential Diagnosis? Osteoid Osteoma - - Osteoblastoma - - Solid Aneurysmal Bone Cyst

13. Diagnosis: Osteoid Osteoma Dx Confirmed by: CT, MRI, and histologic examination

14. DISCUSSION