Pretherapeutic staging of hypopharyngeal carcinoma. Clinical findings, computed tomography, and magnetic resonance imaging compared with histopathologic evaluation.

Abstract

To assess the accuracy of preoperative computed tomography (CT), magnetic resonance imaging (MRI), and clinical and endoscopic tumor evaluation and to analyze the impact of these diagnostic modalities on pretherapeutic staging of hypopharyngeal carcinoma. Prospective study of 44 consecutive patients with hypopharyngeal carcinoma undergoing surgical resection. Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital, Bern, Switzerland. All patients underwent contrast-enhanced CT, MRI at 1.5 T, indirect laryngoscopy, and direct laryngoscopy. The surgical specimens were cut in whole-organ slices parallel to the plane of the axial CT and MRI scans. The histologic findings were compared with the findings of the different diagnostic modalities. The main tumor site was misdiagnosed by endoscopy in 7 (16%) of 44 patients and by CT and MRI in 16 (36%) of 44 patients. Neoplastic invasion of cartilage was present in 21 (48%) of 44 laryngectomy specimens. Magnetic resonance imaging was more sensitive in detecting neoplastic invasion of cartilage than CT (97% vs 68%; P = .002). Magnetic resonance imaging was less specific than CT (62% vs 84%; P = .02), taking into account the thyroid and cricoid cartilages. There was no difference between the overall accuracy of CT and MRI in detecting neoplastic invasion of cartilage (78% vs 75%). Clinical and endoscopic evaluation failed to correctly stage 16 (36%) of 44 patients. Combined clinical and CT evaluation and combined clinical and MRI evaluation failed to correctly stage 12 and 13 of 44 patients, respectively. The assessment of tumor site is more accurate using endoscopic evaluation than CT or MRI. Magnetic resonance imaging is more sensitive in detecting neoplastic cartilage invasion than CT, whereas CT is more specific. Clinical and endoscopic evaluation of tumor stage alone fails to identify invasion of the laryngeal framework. Therefore, many tumors staged pT4 are clinically understaged. The preoperative staging accuracy was improved by combining the information gained using both clinical evaluation and CT or MRI. However, there was no difference in the staging accuracy between CT and MRI.