MR imaging of tumor-like swelling in the submandibular region

摘要

Tumor-like swellings in the submandibular region were evaluated in seven patients with MR imaging. Two cases of pleomorphic adenoma and two of sialoadenitis were selected as examples of submandibular gland lesions, while a plunging ranula, dermoid cyst and lymphadenitis were selected as examples of extraglandular lesions. The pleomorphic adenoma was connected with the remaining gland on T1-weighted images. The sialoadenitis showed changes in the size, signal intensity and homogeneity of the submandibular gland itself. On the other hand, extragland lesions showed zonal interpositions between the lesion and the submandibular gland, which showed either low or high signal intensity on T1-weighted images. On T1-weighted images, the intensity of all of the lesions was either lower than or the same as the normal submandibular gland. On the other hand, all lesions showed higher signal intensity, ranging from slight to very high on T2-weighted images. Sharp margins were seen in all lesions except one sialoadenitis. The sialoadenitis showed inflammatory infiltration into the surrounding tissue. A homogeneous internal pattern was observed in the case of cystic lesions, while an inhomogeneous internal pattern was noted in the pleomorphic adenoma and in the inflammatory lesions. Gd-DTPA enhanced the T1-weighted images in three cases. Pleomorphic adenoma and lymphadenitis were enhanced inhomogeneously, whereas the ranula was not enhanced.