PMC6276445_01
(a, b) A radiograph shows an epiphyseal osteolytic lesion in the end of the right femur (arrow).
CRIOR2018-8030862.001.jpg
PMC6276445_01_CRIOR2018-8030862.001.jpg
fig1
An anteroposterior plain radiograph revealed the osteolytic lesion surrounding by the bone sclerotic lesion in the lateral femoral condyle (Figures 1(a) and 1(b)).
Coronal T1-weighted MR image shows a low-signal-intensity lesion (arrow).
CRIOR2018-8030862.002.jpg
PMC6276445_01_CRIOR2018-8030862.002.jpg
fig2
T1-weighted (T1W) and T2-weighted (T2W) images (Figure 2). The orthopedic physician made a diagnosis of osteochondritis dissecans.
(a) Coronal T1-weighted MR image reveals the lesion growing larger. (b, c) Sagittal T1 and T2-weighted images show a low-signal-intensity lesion (arrow).
CRIOR2018-8030862.003.jpg
PMC6276445_01_CRIOR2018-8030862.003.jpg
fig3
After 13 months, the patient underwent MRI of the knee once more, which demonstrated that the osteolytic lesion grew larger and now measured 16 mm x 10 mm x 10 mm (Figures 3(a)-3(c)).
Arthroscopy showed the depressed lesion like a dimple at the lateral condyle of the femur.
CRIOR2018-8030862.004.jpg
PMC6276445_01_CRIOR2018-8030862.004.jpg
fig4
Arthroscopy revealed a depressed lesion, such as the dimple at the lateral condyle of the femur (Figure 4).
After the curettage of the tumor, the tumor was completely resected and the subchondral bone appeared to be intact.
CRIOR2018-8030862.005.jpg
PMC6276445_01_CRIOR2018-8030862.005.jpg
fig5
We performed biopsy, and the tumor was removed completely with the sharp curettes and suction during arthroscopy (Figure 5).
The tumor tissue was macroscopically gray-white and contains yellow brown foci.
CRIOR2018-8030862.006.jpg
PMC6276445_01_CRIOR2018-8030862.006.jpg
fig6
The tumor tissue was macroscopically gray-white and contained yellow brown foci (Figure 6).
(a) Hematoxylin-eosin staining showed a storiform pattern with giant cells. (b) The tumor did not show nuclear Histone 3.3 G34W immunoreactivity.
CRIOR2018-8030862.007.jpg
PMC6276445_01_CRIOR2018-8030862.007.jpg
fig7
The histological specimen showed a storiform pattern with giant cells (Figure 7(a)). The tumor did not show nuclear Histone 3.3 G34W immunoreactivity (Figure 7(b)).
(a) Coronal computed tomography image shows a bone cavity lesion one month after the surgery. (b) Coronal computed tomography image shows the tumor bone cavity filled with bone formation one year after the surgery.
CRIOR2018-8030862.008.jpg
PMC6276445_01_CRIOR2018-8030862.008.jpg
fig8
Computed tomography revealed that the previous tumor bone cavity was filled with bone formation and no evidence of recurrence (Figure 8).