Chordoma of petrosal mastoid region: A case report

Abstract

Background: Chordoma is a rare low-grade malignant tumor originating from embryonic notochordal tissue mainly occurring in the axial bone, mostly in the spheno-occipital junction and sacrococcyx, which accounts for approximately 1% of all malignant bone tumors and 0.1%-0.2% of intracranial tumors. Chordoma in the petrous mastoid region is rare.

Case summary: We describe a 36-year-old male patient with chordoma in the left petrous mastoid region. The main clinical manifestations were pain and discomfort, which lasted for 2 years. Magnetic resonance imaging showed a lobulated mass in the left petrous mastoid with an unclear boundary and obvious enhancement. The tumor was completely removed after surgical treatment, and a histological examination confirmed that the tumor was a chordoma. During 5 years of follow-up, no clinical or radiological evidence of recurrence or metastasis was found.

Conclusion: Chordoma in the petrosal mastoid region is rare but should be included in differential diagnosis of petrosal mastoid tumors.

Keywords: Bone tumor; Case report; Chordoma; Magnetic resonance imaging; Petrous mastoid; Rare disease.

Figure 1

Brain magnetic resonance imaging before surgery. A, B: T2-weighted axial images (A) and T1-weighted images (B) showed a lobulated mass (white thick arrow) in the petrous part and mastoid area of the left temporal bone, swelling to the brain, with isointense and hypointensity signal on T1-weighted images, hyperintensity and slightly hyperintensity signal on T2-weighted images , and there was a small cystic degeneration area inside (white fine arrow), the surrounding bone was damaged, and the left cerebellar hemisphere was compressed to deformation; C: Fluid-attenuated inversion recovery coronal magnetic resonance imaging (MRI) showed a mass with hyperintensity signal (white thick arrow), and the boundary was clear; D: T1-enhanced axial sequence showed uneven obvious contrast enhancement. There was no enhancement in the cystic degeneration area (white small arrow). Brain MRI at 5 years after surgery; E, F: T2-weighted axial images (E) and T1-weighted images enhanced (F) sequence showed postoperative changes in the left mastoid area, but no definite abnormal signs were found.

Figure 2

Histological examination of chordoma. A: Epithelioid polygonal cells with clear or palely eosinophilic cytoplasm arranged in clusters and cords (hematoxylin and eosin, 100×). B: Immunohistochemical examination showed positive expression of epithelial membrane antigen (magnification 100×).