case_images: PMC5433411_01
case_images: Normal findings at plain radiography.
case_images: CRIOR2017-5846368.001.jpg
case_images: PMC5433411_01_CRIOR2017-5846368.001.jpg
case_images: fig1
case_images: Left knee radiographs showed no abnormalities (Figure 1).
case_images: T2 weighted images (a and c) showed the hypointense lesion (yellow arrow) located at tibia anteromedial plateau with ill-defined bone marrow edema; (b) T1 weighted image showed the well-defined bordered hypointense lesion (yellow arrow).
case_images: CRIOR2017-5846368.002.jpg
case_images: PMC5433411_01_CRIOR2017-5846368.002.jpg
case_images: fig2
case_images: Second MRI, which is recent, showed a nidus-like view with bone marrow edema (Figure 2).
case_images: Coronal (a), axial (b), and sagittal (c) CT images showed the perinidal sclerosis with centrally calcified nidus (yellow arrow) consistent with an osteoid osteoma.
case_images: CRIOR2017-5846368.003.jpg
case_images: PMC5433411_01_CRIOR2017-5846368.003.jpg
case_images: fig3
case_images: CT scans showed a small radiolucent zone, surrounded by reactive circumferential sclerosis, which is typical for osteoid osteoma (Figure 3).
case_images: Intraoperative photo that shows surface discoloration over the lesion.
case_images: CRIOR2017-5846368.004.jpg
case_images: PMC5433411_01_CRIOR2017-5846368.004.jpg
case_images: fig4
case_images: Intervention area was detected after the discolored and irregular lesion surface was marked (Figure 4).
case_images: Photomicrograph of the lesion revealing abundant osteoid formation characteristic of an osteoid osteoma [H&E, x4 obj. (a), x10 obj. (b)].
case_images: CRIOR2017-5846368.005.jpg
case_images: PMC5433411_01_CRIOR2017-5846368.005.jpg
case_images: fig5
case_images: Histopathological examination of the surgically removed lesion confirmed the initial diagnosis of osteoid osteoma (Figure 5).