Comparison of the sonographic features of acalculous and calculous submandibular sialadenitis.

OBJECTIVE: The purpose of this study was to compare the sonographic features of acalculous and calculous sialadenitis of the submandibular gland.

METHODS: A retrospective review of sonograms of the neck was performed in 25 patients with submandibular sialadenitis: 8 with acalculous and 17 with calculous disease. The submandibular glands were assessed for size, shape, border, and echogenicity; presence of dilated ducts or other intraglandular lesions; inflammatory changes in adjacent tissues; lymphadenopathy; and involvement of other salivary glands.

RESULTS: In the group with acalculous sialadenitis, 4 (50%) of the 8 patients had unilateral disease, and 11 (92%) of 12 glands were rounded. In all cases (100%), multiple hypoechoic lesions were diffusely distributed throughout the submandibular glands against a heterogeneous parenchymal background. The lesions ranged from 3 to 15 mm and were oval or round. Confluent lesions were noted in 2 glands (17%). There was no sonographic evidence of duct dilatation, calculi, or abnormal lymph nodes. All patients with calculous sialadenitis had unilateral disease; 9 had a main duct calculus (53%), 7 had intraglandular calculi (41%), and 1 had both (6%). In 14 (82%) of 17 glands, normal shape was maintained, and 11 (65%) of 17 had duct dilatation.

CONCLUSIONS: Acalculous submandibular sialadenitis differs from the calculous form of the disease. The former has characteristic sonographic features, including a round gland with numerous hypoechoic lesions in a heterogeneous parenchymal background. Sonographic imaging in conjunction with fine-needle aspiration is useful for detection of this disorder.