Fig 3.

A 54-year-old woman with type 1 BCA in the left parotid gland. A, Plain CT shows a round nodule with homogeneous attenuation located at the superficial region of the superficial lobe (white arrow). B, The tumor shows slight heterogeneous enhancement with a small, low attenuation component (black arrowheads) on contrast CT. C, Sonography shows well-defined heterogeneously hypoechoic lesion. D, Correlated to the low attenuation component on the postcontrast CT, a photomicrograph of a tumor section (hematoxylin-eosin stain; ×50) shows a collagen component (thick arrows).