First report of primary tonsillar salivary gland adenocarcinoma in a dog

A 9-year-old, female, spayed, mixed breed dog was presented for diagnosis of adenocarcinoma of the minor salivary glands of the right tonsil by histopathology. A whole-body computed tomography scan showed no detectable abnormalities in the major salivary glands. No pulmonary metastasis or lymphadenopathy was noted. An anaesthetised oropharyngeal examination revealed an erythematous and irregular broad-base mass in the right tonsil, and an erythematous and slightly irregular nodular area in the contralateral tonsil. Bilateral excisional biopsies of the tonsils via tonsillectomies were performed for definitive diagnosis. Histopathology of the right tonsillar mass was consistent with an incompletely excised adenocarcinoma of the minor salivary gland, and reactive lymphoid hyperplasia of the contralateral tonsil. Based on this case report, it is important to consider salivary adenocarcinoma as a differential diagnosis for primary tonsillar tumour, as there are lobules of salivary glands in normal canine tonsils.