Magnetic resonance imaging assessment of tumorous lesions in the floor of the mouth: case reports and review of the literature

Objectives Magnetic resonance (MR) imaging may provide some information as to the extent and tissue characteristics of a cancerous mass, but the imaging features of lesions in the floor of the mouth have not been sufficiently clarified. MR imaging features of tumescent lesions in this region were characterized, and the differential diagnoses are discussed. Methods MR images of 12 patients with tumescent lesions in the floor of the mouth (three patients with squamous cell carcinoma, two with adenoid cystic carcinoma, one with hemangioma, one with schwannoma, one with lipoma, and four with ranula) were reviewed. The literature on the imaging features of tumescent disease in the floor of the mouth was searched using the Medline database. Results Six types of tumescent lesions in the floor of the mouth are presented. The differential diagnosis through a review of the references is discussed. Malignant tumors were demonstrated as ill-defined masses. MR images were good at showing the internal structures, such as fluid, hemorrhage, fat, nerves, calculus (phlebolith), cholesterol, and keratin, as different signal intensities. Therefore, MR images gave clues for the differential diagnosis. Conclusion MR images presented the distinctive features or the extent of the lesions and were therefore considered useful for a more accurate diagnosis prior to treatment.