P212 Scientific Posters Otolaryngology- Head and Neck Surgery August 1999 tated, cystic lesion was demonstrated with dimensions of 5.0 • 1.0 • 1.5 cm. Areas of postgadolinium enhancement were noted. The patient was referred for consultation and subse- quently underwent superficial parotidectomy with placement of a fat graft for facial contouring. Given the narrow resection of margins and presence of adenocarcinoma on final patholo- gy, the patient was advised to undergo radiation therapy to the parotid bed and lymphatic drainage areas. At 2-year follow- up, no evidence of recurrent tumor had been detected. Results: Frozen sections suggested a pleomorphic adeno- ma, with additional features consistent with microscopic Warthin's tumor. Extension was present to within 1 mm of the resected deep margin. Two foci of invasive carcinoma were noted, including 1 nest in khe parotid capsule. Final histology identified an intraparotid lymph node (1 of 5) containing microscopic Warthin's tumor. Due to unusual neoplasm fea- tures, a consultation was performed between the Departments of Pathology at the University of Pennsylvania, the Columbia College of Physicians & Surgeons, and the University of Pittsburgh. The final report identified the following tumors: (1) papillary cystadenoma lymphomatosum (Warthin's tumor); (2) benign mixed tumor; (3) adenocarcinoma, intra- ductal and microinvasive; and (4) benign mixed tumor with oncocytic features. Conclusion: Consensus exists on 2 aspects of salivary pathology: (1) the complement of expressed markers is influ- enced by the site of origin, and (2) neoplasms arising from proximal duct cells share a greater malignant potential than those arising distally. Overall, Warthin's tumors are most commonly associated with a distinct, synchronous tumor. A review of the literature revealed 43 such cases, with 29 malig- nancies. The hypothesis that a second neoplasm arises from Warthin's tumor, rather than de novo, is supported by histo- logic demonstration of benign to malignant transitional zones in other reported cases. This report represents the first instance of the rare intraductal adenocarcinoma (<1% of parotid tumors) existing with papillary cystadenoma lym- phomatosum. Radiologic findings and histologic features will be presented. 33 Reconstructed Oblique Longitudinal Temporal Bone HRCT SPIROS MANOLIDIS MD; LING-LING CHAN MD; KATHERINE H TABERPHD; L ANNE HAYMAN MD; Houston IX Objectives: To evaluate the clinical utility of evaluating the in vivo anatomy of the temporal bone in a nonorthogonal plane, parallel to the axis of the temporal bone. Methods: HRCTs of 10 normal temporal bones were eval- uated as follows. Two image sets were assessed: (1) direct axial and coronal, and (2) oblique sectional reformats along the longitudinal axis of the temporal bone as defined by the plane of the superior semicircular canal. Three measurements from direct axial and reconstructed axial sections (n = 9) were compared with cadaver values. Twenty-one anatomic relation- ships were measured in these oblique longitudinal recon- structed images (n = 10). Results: The comparison between axial cadaver measure- ments and direct axial CT and reconstructed axial CT mea- surements showed no differences. There was no difference between age, sex, or side in any of the 21 reconstructed oblique longitudinal HRCT measurements. Several of these anatomic relationships cannot be visualized in the orthogonal planes and are thus novel. The clinical significance of these measurements, as well as the imaging of the temporal bone in the oblique longitudinal plane, a plane familiar to most sur- geons, is discussed. Conclusion: This paper presents a practical measurement protocol for rapidly evaluating anatomical relationships in a novel plane that is applicable to most temporal bone surgery. This defines in vivo novel anatomical relationships in an oblique plane longitudinal to the long axis of the temporal bone. The nonorthogonal plane of orientation closely approx- imates the visual angle of most temporal bone and skull base surgery, thus defining anatomical relationships that are more relevant to surgical orientation. This decreases the likelihood of surgical mishaps and improves teaching of surgical tempo- ral bone anatomy. 34 Bilateral Ethmoidal Mucocele as the Initial Manifestation of Cystic Fibrosis DANIELA CURTI THOME MD; OSSAMU BUTUGAN MD PHD; RICHARD L VOEGELS MD; Sao Paulo Brazil Objectives: To report a rare and interesting case of a child who presented a bilateral ethmoidal mucocele as the initial manifestation of cystic fibrosis (mucoviscidosis). Methods: A 10-month-old white boy was referred to the Otolaryngologic Department of University Sat Paulo Medical School for evaluation of a progressive bilateral nasal obstruc- tion associated with nasal discharge. The patient had no histo- ry of any other disease, except a significant poor nutritional status. The parents had noticed an aggravation in the child's respiratory distress during the previous 2 months. Coronal and axial paranasal sinus CT scans showed a bilateral ethmoid sinus homogeneous well-delimited opacification almost com- pletely obliterating the nasal cavities. Resection of the masses was performed using a conservative endonasal endoscopic approach. The histopathologic study demonstrated bilateral ethmoidal mucoceles. Concerning the child's nutritional sta- tus, further investigations were performed after surgery that revealed cystic fibrosis. Results: No postoperative complications developed, and the child has had no evidence of nasal obstruction after a 4- month follow-up, presenting a good respiratory pattern. The