Salivary Mucocele

By: April Guille, DVM, Diplomate ACVS

A salivary mucocele, or a sialocele, is a collection of saliva in the subcutaneous tissues near the site of a leaking salivary duct or gland. The most common gland affected is the sublingual salivary gland, but any of the four major salivary glands can cause a sialocele. The location of the swelling often determines the presenting signs and indicates the involved salivary gland. The two most common locations of saliva collection are the ventral cervical area and under the tongue, although swelling can occur in the pharyngeal area, causing dyspnea, or under the ventral orbit, leading to exophthalmos. Animals with labored breathing due to a pharyngeal sialocele are in danger of airway obstruction and the swelling should be opened up for immediate drainage. Sialoceles can be caused by trauma, sialoliths, neoplasia, foreign bodies, or recent oral surgery, but often the cause is unknown. No sex predisposition has been found; dachshunds, poodles, Australian silky terriers, and German shepherds are predisposed.

On aspirate, the fluid is often viscous and clear or blood-tinged with small to moderate numbers of nondegenerate nucleated cells in a proteinanceous background. Conservative treatment by drainage alone is not recommended due to the high rate of recurrence. Definitive treatment involves removing the affected glands along with drainage; ranulas and pharyngeal sialoceles are treated with marsupialization. Although the sublingual gland and duct system are the most commonly affected, removal of the sublingual gland requires removal of the mandibular gland as well due to their common capsule and close association. The prognosis is excellent with complete removal of the gland, with a recurrence rate of less than 5 percent.

Facts about Sialoceles

Four main presentations include exophthalmos, labored breathing, dysphagia, or ventral cervical swelling

Sublingual salivary gland is the most commonly affected gland

Surgical removal of the affected gland is recommended to prevent recurrence

Excellent prognosis with surgery