Diagnostic value of capsule-like rim enhancement on magnetic resonance imaging for distinguishing malignant from benign parotid tumours.
The purpose of this study was to clarify the diagnostic value of capsule-like rim enhancement (CLRE) on magnetic resonance imaging (MRI) for distinguishing malignant from benign tumours of the parotid gland. We retrospectively evaluated contrast-enhanced T1-weighted images of 100 patients with malignant and benign parotid tumours for the presence, completeness, and irregularity of CLRE and its maximum thickness. We investigated any correlation of imaging and histopathological findings for 51 cases showing CLRE with available histology. The presence and completeness of CLRE did not differ significantly between benign and malignant tumours. Malignant tumours had more irregular CLRE than benign tumours (P<0.05). The mean CLRE thickness was significantly greater for malignant (2.4 mm) than benign tumours (1.4 mm) (P<0.0001). The two types of tumour were most accurately distinguished using a cut-off value of 1.5 mm thickness. Histopathology demonstrated the general correspondence of thick CLRE on MRI in malignant tumours with thick but sparse fibrous tissue and infiltration of tumour cells and lymphocytes, whereas thin CLRE in benign tumours typically represented dense fibrous tissue without infiltration of tumour cells. CLRE was more irregular and thicker in malignant tumours than in benign tumours, which may be of help in differentiating them.
Department of Oral Diagnosis, Tohoku University Graduate School of Dentistry, Aoba-ku, Sendai, Japan.
M
M
Sakamoto
Department of Oral Diagnosis, Tohoku University Graduate School of Dentistry, Aoba-ku, Sendai, Japan.
M
M
Iikubo
Department of Oral Diagnosis, Tohoku University Graduate School of Dentistry, Aoba-ku, Sendai, Japan. Electronic address: ikh-koji213@umin.ac.jp.
I
I
Kojima
Department of Oral Diagnosis, Tohoku University Graduate School of Dentistry, Aoba-ku, Sendai, Japan.
T
T
Sasano
Department of Diagnostic Radiology, Tohoku University Graduate School of Medicine, Aoba-ku, Sendai, Japan.
S
S
Mugikura
Department of Diagnostic Radiology, Tohoku University Graduate School of Medicine, Aoba-ku, Sendai, Japan.
T
T
Murata
Department of Pathology, Tohoku University Graduate School of Medicine, Aoba-ku, Sendai, Japan.
M
M
Watanabe
Department of Otolaryngology, Head and Neck Surgery, Tohoku University Graduate School of Medicine, Aoba-ku, Sendai, Japan.
K
K
Shiga
Department of Otolaryngology, Head and Neck Surgery, Tohoku University Graduate School of Medicine, Aoba-ku, Sendai, Japan.
T
T
Ogawa
Department of Diagnostic Radiology, Tohoku University Graduate School of Medicine, Aoba-ku, Sendai, Japan.
S
S
Takahashi
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010307:Parotid Neoplasms / Q000473:pathology* / Q000601:surgery; D012189:Retrospective Studies
D003287:Contrast Media; D019786:Gadolinium DTPA
Head/neck; MRI; Neoplasms – primary; Salivary glands