case_images: PMC9852635_01
case_images: Preoperative MRI and CT images: (A) coronal MRI images showed a mass at the left articular tubercle. (B) Coronal CT images showed a heterogeneous mass at the left articular tubercle. (C) Sagittal CT images showed the same. (Red arrows indicates the lesion).
case_images: fsurg-09-1033342-g001.jpg
case_images: PMC9852635_01_fsurg-09-1033342-g001.jpg
case_images: F1
case_images: CT (CBCT) and magnetic resonance imaging (MRI), which showed anterior displacement of the left disc, and local swelling was detected on the anterior and lateral sides of the left temporal articular tubercle, with interrupted continuity of the cortical bone (Figure 1A). CBCT showed a heterogeneous mass sized approximately 14.5 mm * 10 mm * 8 mm at the left temporal articular tubercle (Figures 1B,C).
case_images: Surgical intervention and radiological change in CBCT images: (A) lesion resection at the left articular tubercle; (B) stitches of the incision and high vacuum drainage device placement; (C-E) CBCT images of the lesion area preoperatively, immediately postoperatively and one month postoperatively, respectively. (Red dotted lines show the border the articular tubercle region).
case_images: fsurg-09-1033342-g002.jpg
case_images: PMC9852635_01_fsurg-09-1033342-g002.jpg
case_images: F2
case_images: During the operation, a pre-auricular incision was made, the tumor was resected (Figure 2A), followed by curetting to the area with relatively normal bone, reshaping the articular eminence, disc manipulation was not performed, and finally, suturing the incision carefully and placing a high vacuum drainage device (Figure 2B). Immediately post-operative CBCT (Figure 2D) revealed the resection range compared with that pre-operatively (Figure 2C). CBCT postoperatively (Figure 2D), which indicated that there were no signs of recurrence. Considering the huge trauma a second surgery will cause and the complete relief of his symptoms after recovering from the surgery, the patient chose to keep a regular follow-up to detect any recurrence instead of an immediate second surgery.
case_images: Histopathological features (H&E staining): (A) immature trabeculae rimmed by osteoblasts; (B) giant cells with multiple dense nuclei and cellular atypia can be found. H&E, Hematoxylin and eosin.
case_images: fsurg-09-1033342-g003.jpg
case_images: PMC9852635_01_fsurg-09-1033342-g003.jpg
case_images: F3
case_images: It showed that the tumor was composed of haphazardly mineralized trabeculae of bone, osteoid rimmed by osteoblasts, and acellular vascular fibrous stroma (Figure 3A). There were giant cells with multiple dense nuclei, and cellular atypia can also be seen (Figure 3B), but no epithelioid osteoblast was seen within sight. SOX2 (Figure 4C) and MDM2 (Figure 4D) indicated that the lesion was osteogenic. Scattered positive expression of CD68 (Figure 3E) proved the presence of multinucleated osteoclasts.
case_images: Immunohistopathological results: (A) Ki-67 (<5%); (B) PCNA (<5%); (C) SOX2 (+); (D) MDM2 (+); (E) CD68 scatteredly expression (+).
case_images: fsurg-09-1033342-g004.jpg
case_images: PMC9852635_01_fsurg-09-1033342-g004.jpg
case_images: F4
case_images: PCNA (Figure 4B) labeling index were low (<5%), indicating that the proliferation capacity is relatively normal. Positive expression of SOX2 (Figure 4C) and MDM2 (Figure 4D) indicated that the lesion was osteogenic. Scattered positive expression of CD68 (Figure 3E) proved the presence of multinucleated osteoclasts.