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In this retrospective study, the accuracy of preoperative staging by high-resolution CT and clinical evaluation (indirect-direct laryngoscopy) is compared to the postsurgical pathologic staging of laryngeal cancer. Forty-two patients who were admitted to St. Louis University Hospital between the years of 1978 to 1985 with diagnoses of laryngeal cancer were included. All patients received high-resolution CT scan of the larynx preoperatively and subsequently underwent total or partial laryngectomy. None of these patients received preoperative radiotherapy. The accuracy of the clinical vs. CT staging--as well as the accuracy of the staging by combination of the two modalities--was determined by comparison with the postsurgical pathologic staging. The accuracy was assessed separately for glottic, supraglottic, and transglottic carcinoma. The accuracy of CT staging for glottic carcinoma was 75%. However, clinical evaluation in this group of lesions was very reliable, offering 92.9% accuracy. The accuracy of CT staging increased in the supraglottic and transglottic lesions, to become superior to the clinical staging. With combined information gained by both examinations, the preoperative staging accuracy was 91.4% for supraglottic carcinoma and 87.5% for transglottic carcinoma. It is, therefore, recommended that high-resolution CT should be included in the preoperative staging of laryngeal cancer.

The larynx is separated into compartments bounded by connective tissue membranes and cartilages. The membranes and cartilages affect the localization and spread of cancer for a while, but invasion eventually occurs. Histological study of the cartilages in the earliest stages of invasion shows cancer cells growing between the collagen bundles where the connective tissue membranes attach to the cartilages. At these points, the collagen bundles pass obliquely through the perichondrium to anchor into the cartilage and bone like Sharpey's fibers. As the cancer cells multiply, they separate the collagen bundles, forming linear passageways through the perichondrum. This appears to be the mechanism for cartilage invasion. Thus the sites of attachment of the strongest membranes are also the most frequent sites of invasion, i.e., the anterior commissure tendon and the cricothyroid membrane.

The gross anatomy course at St. Louis University was designed to utilize peer teaching. Eight students are assigned to each cadaver and they work in teams of two, so that every student does one out of every four dissections. During one class period, the lecture for a unit is given to all class members, followed by a prosection demonstration to only the dissectors of that unit (one‐fourth of the class). At the beginning of the following class period, the dissectors give a prosection demonstration of their dissection to the other six student assigned to their cadaver. The lecture and prosection demonstrations for the next unit are given to the next team of dissectors as above. The students anonymously evaluate the course each year. Passing Part I of the National Board Examinations is required. For 12 years, the National Board Unit Examination of gross anatomy was given as the final examination for the course. The course is liked by the students, can be taught with a minimal number of faculty, utilizes only half the cadavers of a traditional course, has less contact hours than the national average, yet students do better than the national average on the anatomy part of the National Board Examination. © 1992 Wiley‐Liss, Inc.