To explore the ultrasonographic features of salivary acinic cell carcinoma (ACC) and analyze the corresponding pathological basis.

Thirty-nine patients with acinic cell carcinoma between July 2003 and November 2019 confirmed by surgery and pathology at Shanghai Municipal Hospital of Traditional Chinese Medicine and Fengcheng Hospital of Fengxian District were retrospectively analyzed. Ultrasonographic features, including the boundary, internal echo, morphology, posterior echo, and cystic and/or solid mixed echo, were summarized. The pathological data and the sonographic images were comparative analyzed.

There were 37 cases (94.9%) occurring in the parotid gland and 2 cases in the submandibular gland. Most of the lesions were showed a clear boundary (28/39, 71.8%). Pathology showed that the tumors had envelopes in 33 cases (33/39 84.6%), the envelopes were incomplete, and oval and lobular morphology was common (33/39, 84.6%). The majority of lesions had hypoechoic (24/39 61.5%) and mixed echo (14/39,35.9%), the internal echo was heterogeneous (25/39, 64.1%), and echo enhancement occurred behind most masses (32/39, 82.1%). Pathological analysis suggested that 27 cases (27/39 69.2%) had a large amount of jelly-like PAS positive substances in the intercellular space. Color Doppler flow imaging (CDFI) signal was not abundant in 20 cases (20/39, 51.3%). Pathology showed that tumor vascular density was sparse in 18 cases (18/39 46.2%).

ACC has some ultrasonographic features and corresponding pathological basis, but its malignant signs are not typical, so the qualitative diagnosis of ACC by ultrasonography has some limitations, and the diagnostic accuracy needs to be further improved.