Bilateral sialocele associated with osseous metaplasia in a dog

Sialocele is a lesion characterized by a cavity filled with saliva and delimited by granulation tissue and is the most commonly observed condition in dogs' salivary glands. A cervical swelling was observed in a male, mixed breed, 12-year-old dog. When punctured, the local was filled with saliva. The animal was referred for sialoadenectomy, and bilateral involvement was observed, with stony material delimiting the sialoceles on both sides. Samples were sent for histopathological examination, which showed cavity areas without epithelial delimitation, with osseous metaplasia and chronic inflammation. Such characteristics allowed the diagnosis of bilateral sialocele associated with osseous metaplasia. The presence of osseous metaplasia in sialoceles is extremely rare, with only four other cases described, which makes it difficult to reach conclusions related to epidemiology and pathogenesis.