Locally advanced sinonasal squamous cell carcinoma presenting as oral pain in a dog

Abstract An 11‐year‐old, female, spayed, mixed breed dog was presented with a 1‐month history of oral pain. No major physical abnormalities were reported. A comprehensive oral examination was recommended. At intubation, temporomandibular joint crepitus and decreased range of motion were observed. Three teeth were surgically extracted following the diagnosis of advanced external resorption. Four months later, the dog was reassessed for persistent oral pain. Right‐sided dorsomedial periocular and nasal bone swelling, obscured by long facial hair, was appreciated. Computed tomography revealed a large right caudal sinonasal mass with extensive bony lysis. Palliative care was elected following a presumptive diagnosis of neoplasia. Cytology of the nasal mass was most consistent with squamous cell carcinoma. This advanced case of sinonasal squamous cell carcinoma with an atypical clinical presentation and subtle physical exam findings highlights the importance of performing a thorough physical examination and considering all identified abnormalities while refining a diagnosis.