case_images: PMC6595646_01
case_images: Left retroauricular lesion.
case_images: 10.1177_1179556519855381-fig1.jpg
case_images: PMC6595646_01_10.1177_1179556519855381-fig1.jpg
case_images: fig1-1179556519855381
case_images: A 16-year-old girl was referred to our service for a rapidly progressive left retroauricular lesion incidentally discovered 3 weeks earlier (Figure 1).
case_images: Preoperative noncontrast CT scan showing an ill-defined lesion with sunburst periosteal reaction over the left mastoid bone (arrows). (A) Axial view. (B) Coronal view. CT indicates computed tomography.
case_images: 10.1177_1179556519855381-fig2.jpg
case_images: PMC6595646_01_10.1177_1179556519855381-fig2.jpg
case_images: fig2-1179556519855381
case_images: An aggressive periosteal reaction with a sunburst appearance was also described (Figure 2).
case_images: Preoperative MRI. (A) Axial T1W1 with isointense signal lesion (asterisk). (B) Coronal T2W1 with hypointense signal lesion (arrow). MRI indicates magnetic resonance imaging.
case_images: 10.1177_1179556519855381-fig3.jpg
case_images: PMC6595646_01_10.1177_1179556519855381-fig3.jpg
case_images: fig3-1179556519855381
case_images: The lesion was strictly confined to the outer cortex of the temporal bone (Figure 3).
case_images: Left partial mastoidectomy with wide surgical margins. (A) Surgical deficit following complete en bloc resection of the tumour. (B) Pathological specimen.
case_images: 10.1177_1179556519855381-fig4.jpg
case_images: PMC6595646_01_10.1177_1179556519855381-fig4.jpg
case_images: fig4-1179556519855381
case_images: The patient had a left partial mastoidectomy with gross surgical margins between 1 and 1.5 cm (Figure 4).
case_images: Hematoxylin and eosin (HE) immunostaining. (A) Low power view showing a low-grade fibro-osseous lesion (HE40x). (B) Bland spindle cells in a fibrous background, with islands of woven bone (HE100x). (C) Focus of woven bone which appears to be partially surrounded by osteoblasts (HE200x). (D) Bland spindle cells in a fibrous background, with islands of woven bone (HE200x).
case_images: 10.1177_1179556519855381-fig5.jpg
case_images: PMC6595646_01_10.1177_1179556519855381-fig5.jpg
case_images: fig5-1179556519855381
case_images: Woven bone with only scant lamellar bone was noted and no prominent osteoblastic population were found along bone trabeculae (Figure 5).