Maxillofacial Surgery Maxillofacial Reconstruction and Function Division of Maxillofacial and Neck Reconstruction, Tokyo Medical and Dental University
Histology, Oral and maxillofacial region, Schwannoma, Ultrasound
Ultrasonographic study of a schwannoma of the oral and maxillofacial region have rarely been reported. Here we report
ultrasonographic findings from the nine cases of schwannoma located in that region that we encountered between 1984 and 1995.
The tumor was delineated as a low echoic mass with a sharply demarcated contour and posterior echo enhancement. Change in
the internal echo followed pathologic degenerative changes: cystic change, bleeding, myxomatous change, and hyaline
degeneration. The internal echo was in agreement with the description of Antoni type A tissue, showing hemorrhagic and
hyaline degeneration in the tumor. The cystic pattern of the ultrasonogram corresponded to cystic change, and hypoechoic area
of the ultrasonogram corresponded to Antoni type B tissue and myxomatous change. The internal echo pattern on the
ultrasonogram of a schwannoma was found to reflect the pathologic structure of the tumor.