MR imaging of benign and malignant lesions in the buccal space.
OBJECTIVE
To evaluate MRI characteristics of buccal space lesions and to discuss the sensitivity of MRI in predicting malignancy of those lesions.


METHODS
Thirty patients with malignant (n=7) or benign (n=23) lesions originating in the buccal space were reviewed retrospectively. MR images were assessed for the margins, internal architecture, signal intensity of lesions and their relation to the surrounding structures.


RESULTS
Two cases of soft tissue sarcoma were shown as ill-defined masses with infiltration into adjacent muscles and bone. On the other hand, all tumors of minor salivary gland origin, whether malignant (n=4) or benign (n=2), were well-defined and confined within the buccal fat pad without infiltration into surrounding structures. All haemangiomas (n=9) had very high T2-weighted signal intensity. Three out of them contained signal voids on all sequences thought to represent phleboliths, a finding strongly suggestive of the diagnosis. Inflammatory lesions were characterized by the presence of edema in the surrounding fat. When ill-defined margins, infiltration into muscles and bone destruction were used as the criteria for the malignancy, only two out of seven malignant tumors were correctly diagnosed (sensitivity 29%).


CONCLUSIONS
Although MR imaging was useful in demonstrating the extent of buccal space lesions, its diagnostic value in predicting malignancy was very limited. It was especially true for malignant tumors of minor salivary gland origin, which were typically seen as well-defined masses without infiltration into surrounding structures on MRI.
Kurabayashi
T
T
Oral and Maxillofacial Radiology, Graduate School, Tokyo Medical and Dental University, Japan. kura.orad@tnd.ac.jp
Ida
M
M
Tetsumura
A
A
Ohbayashi
N
N
Yasumoto
M
M
Sasaki
T
T
D000273:Adipose Tissue / Q000473:pathology; D002610:Cheek / Q000473:pathology*; D003287:Contrast Media; D004487:Edema / Q000473:pathology; D005147:Facial Bones / Q000473:pathology; D005152:Facial Muscles / Q000473:pathology; D005153:Facial Neoplasms / Q000175:diagnosis* / Q000473:pathology; D019786:Gadolinium DTPA; D006391:Hemangioma / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D020347:Lithiasis / Q000175:diagnosis; D008279:Magnetic Resonance Imaging; D009062:Mouth Neoplasms / Q000175:diagnosis* / Q000473:pathology; D009361:Neoplasm Invasiveness; D012189:Retrospective Studies; D012468:Salivary Gland Neoplasms / Q000175:diagnosis / Q000473:pathology; D012470:Salivary Glands, Minor / Q000473:pathology; D012509:Sarcoma / Q000175:diagnosis / Q000473:pathology; D012680:Sensitivity and Specificity; D014652:Vascular Diseases / Q000175:diagnosis
D003287:Contrast Media; D019786:Gadolinium DTPA