Histologically, Kikuchi-Fujimoto disease (KFD) is a necrotising, self-limiting lymphadenitis. It typically affects the lymph nodes of the neck and it is often accompanied by a high fever. The present paper documents the case of a 28-year old male carrier of KFD. From the x-ray images, the KFD clinically appeared to be a submandibular salivary gland tumor. An ultrasound study led us to believe that it was more likely a branchial cyst. Malignant lymphoma can be mistaken for KFD, thus the diagnosis must be precise and the differentiation is crucial.