Sublingual infiltrative lipoma in a dog mimicking a ranula

A 7-year-old neutered female Staffordshire Bull Terrier was referred for a suspected sublingual sialocoele or ranula. The patient had a three-week history of a soft, non-painful, left submandibular swelling that had extended to the intermandibular and sublingual areas. Cytopathological findings from fine-needle aspiration were indicative of either non-representative subcutaneous fat or a lipoma. CT of the head and neck was performed to evaluate these two clinical possibilities further, confirming the presence of a focal, mainly intermandibular, lipoma with a mean precontrast attenuation of −114 Hounsfield Units (HU). Despite the clinical presentation of this patient being more suggestive of a ranula, this case highlights that other differentials should be considered when facing an intermandibular lesion. Advanced imaging modalities can help in assessing the extension and internal characteristics of submandibular swelling in dogs.