The objective of this study was to establish the appropriate interslice gap for screening coronal paranasal sinus tomography to identify sinus mucosal thickening. We reviewed 100 coronal paranasal sinus tomographic scans (interslice gap, 2 mm) that had been performed at our institution between January 2004 and November 2004 to evaluate rhinosinusitis. Digital photographs of all slices from each tomographic scan were taken. The intervening slices were eliminated to form six different sets of interslice gaps of 4, 6, 8, 10, 16, and 20 mm. The remaining slices for each set were moved to corresponding folders created on a computer to catalog each interslice gap. The same specialist evaluated each folder of interslice gap. The paranasal sinuses, the ethmoid infundibulum, and the frontal recess were evaluated for mucosal thickening. The sensitivity, specificity, and accuracy of each interslice gap in detecting mucosal thickening were calculated by accepting the results of 2-mm-thick slices as the gold standard. The interslice gap of 2 mm was compared with that of other interslice gaps using the chi-square test for dependent groups (the McNemar test). The value of 20 mm interslice gap in detecting sinus mucosal thickening was found to be significantly low when compared with the interslice gap of 2 mm (P = 0.022). Using coronal paranasal sinus tomography, an interslice gap up to 16 mm may be used to detect sinus mucosal thickening.

No abstract

Ganglioneuroma is a rare, benign, slow-growing tumor thought to develop from cells of neural crest origin, even though hypotheses on the pathogenesis of that lesion differ. Ganglioneuromas, which do not release excessive catecholamine or steroid hormones, develop primarily in the posterior mediastinum and retroperitoneum. Because of their slow growth, many ganglioneuromas are large when they are diagnosed. In this case report, a 50-year-old woman with hearing loss is described. Magnetic resonance imaging revealed a mass (3 × 4 mm) in the internal auditory canal (IAC). The encapsulated tumor was entirely excised via the middle fossa approach. The results of histopathological examination indicated that the excised lesion was a ganglioneuroma. To our knowledge, this is the first report of a ganglioneuroma of the IAC. We suggest that ganglioneuroma be considered in the differential diagnosis of all tumors of the IAC.

Warthin's tumor is a well-defined salivary gland neoplasm consisting of benign epithelial and lymphoid components. However, malignant transformation is extremely rare and the differential diagnosis of metastasis from an epidermoid carcinoma in Warthin's tumor is important. We present a case with epidermoid carcinoma arising in Warthin's tumor of parotid gland in a 48-year-old woman, and differential diagnosis is discussed.

Plain sinus radiography is the imaging technique most frequently used to investigate suspected rhinosinusitis, but it has low diagnostic sensitivity. Contiguous paranasal computerized tomography (CT) gives detailed information about the pathology, anatomy and anatomical variations of the paranasal sinuses, but this method also has limitations. The cost of using this technique for all cases of suspected rhinosinusitis is prohibitive, and complete CT scans involve considerable radiation exposure. The aim of this study was to devise a CT protocol for diagnosing and following rhinosinusitis that is more economical and involves much less radiation exposure than contiguous CT. In this retrospective study, three physicians independently reviewed the contiguous coronal paranasal CT studies of 136 patients. The study population comprised the adult patients who were investigated for suspected chronic rhinosinusitis. All scans had been obtained at the second visit, after the patient had completed a 3-week course of medical treatment. For each case, the same three slices were selected to form the "three-slice CT" exam, and the same physicians independently evaluated this set. Using the results from the contiguous set as the gold standard, we calculated the sensitivity and specificity of three-slice CT for identifying rhinosinusitis. The sensitivity and specificity of three-slice CT for identifying inflammatory sinus disease were 95.1 and 92.6%, respectively. Three-slice CT is a valuable method for diagnosing and following rhinosinusitis cases, and would be cheaper and involve less radiation exposure than contiguous coronal CT. However, despite the high cost and greater radiation exposure, contiguous CT remains the gold standard for evaluating detailed sinus anatomy and disease progression.