Sonic tumor cells had nuclear goovas. 3 cases showed abundant mitochondria, rough endoplasm reticulum. neurosecretory granules, prozymogen-granule-like particles and annulate lamellae.

瘤细胞有丰富的线粒体及粗面内，分泌颗粒，酶原样颗粒及特征性的环状板层体。