A comparative study of sonographic and histopathologic findings of tumorous lesions in the parotid gland

Objective. The purpose of this study was to clarify which histopathologic f eatures are visualized on sonograms by comparing sonomorphologic and histop athologic analyses of parotid tumorous lesions on the same plane. Study design. Boundaries, shapes, echo intensity level, distribution of int ernal echoes, and acoustic enhancement on sonograms of 86 parotid tumorous lesions were retrospectively compared with the histopathologic findings. Results. Unclear boundaries on sonograms corresponded to abundant connectiv e tissue with scattered tumor cell nests. Polygonal shapes on sonograms wer e revealed to represent tumor cell infiltration on histopathologic sections . The "very hypoechoic" lesions showed significantly high ratio of cystic a reas (P < .05) in Warthin tumor. The weakly hyperechoic structures on sonog rams were connective tissue, hyaline, and necrotic and keratinized material s. Attenuated posterior echoes were observed in malignant tumors with abund ant connective tissue and metaplastic bone formation. Conclusions. To facilitate correct sonographic diagnosis, it is important t o ascertain the correlation between sonomorphology and histopathology.