Hirokazu Nagasawa

Ultrasonography in the diagnosis of palatal tumors

OBJECTIVE The purpose of this study was to evaluate the usefulness of ultrasonography for the preoperative evaluation of palatal salivary gland tumors. STUDY DESIGN Eleven surgically treated patients with salivary gland tumors of the palate were examined retrospectively. Intraoral ultrasonic scanning examinations were performed with a 10-MHz transducer. RESULTS The ultrasonographically well-delimited tumors had a complete capsule histologically, whereas the poorly delimited tumors had no capsule or only an incomplete capsule. The tumors that had a reinforced posterior wall echo were associated with pressure bone absorption, and the tumors that had a reinforced posterior echo were associated with bone destruction. Echograms of the tumors were classified into 4 types on the basis of the internal echoes. CONCLUSIONS Intraoral ultrasonography of palatal tumors can be used to determine the localization and condition of the tumors by close analysis of the echogram. The internal echo pattern on the ultrasonogram of a palatal tumor was found to reflect the pathologic structure of the tumor. Ultrasonography can therefore be a quite useful technique for the preoperative evaluation of palatal salivary gland tumors.

Ultrasonography and computed tomography of extracapsular invasion in cervical lymph nodes of squamous cell carcinoma in the oral cavity

PurposeThis study evaluates the efficacy of imaging for diagnosing extracapsular invasion by metastatic cervical lymph nodes.MethodsThe subjects were 47 patients with squamous cell carcinoma of the oral cavity examined by both ultrasonography and computed tomography. All subjects had undergone neck dissection, and histopathologic examination confirmed the presence of one or more metastatic cervical lymph nodes in each of them.ResultsHistopathologic examination confirmed extracapsular invasion in 25 of 48 metastatic nodes; in the remaining 23 nodes, the tumor was confined within the capsule. Average short-axis diameters of the lymph nodes of these groups differed significantly (17.4 ± 10.6 and 12.7 ± 4.4 mm, respectively; P = 0.046). The diagnostic sensitivity, specificity, and accuracy of ultrasonography for detecting macroscopic extracapsular invasion were 80%, 74%, and 77%, respectively. The corresponding values for computed tomography were 85%, 83%, and 84%.ConclusionDiagnostic images are effective for the preoperative diagnosis of extracapsular invasion of metastatic cervical nodes of carcinoma of the oral cavity.

Ultrasonic study of schwannoma of the oral and maxillofacial region: Comparison of ultrasonograms and pathologic findings

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 hypoechoic 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.