Fig. 3.

Images of a 59-year-old man presenting with a painless left periauricular mass (case 3).

A. The T1-weighted axial MR image shows a well-defined, dumbbell-shaped mass (arrows) that is isointense to the muscle in both the left parapharyngeal space and the parotid space with widening of the stylomandibular tunnel. The mass medially displaces the parapharyngeal fat and the carotid sheath. Multiple hypointense streaks are seen in the mass (open arrow).

B. The T2-weighted axial MR image shows the heterogeneous high signal intensity of the mass (arrows). The streaks are also demonstrated as low signal intensity (open arrow).

C. The contrast-enhanced T1-weighted axial MR image reveals the homogeneously strong enhancement of the mass. The streaks were less enhanced than in the other portion of the tumor.

D. Photomicrograph shows that the tumor is composed of a haphazard proliferation of spindle cells separated from the hyalinized collagen tissue (hematoxylin-eosin, magnification × 200). The inlet shows that the tumor cells and the capillary endothelial cells have immunohistochemically positive CD34 results; this finding is consistent with that of solitary fibrous tumor (original magnification × 200).