XXV Histopathology of Larynges and Radical Neck Specimens

Abstract

Combined therapy of advanced carcinoma of the larynx and laryngopharynx is a 3 phase program consisting of 5500 rads tumor dose of cobalt 60, followed by an interval waiting period of 3 to 6 wK., and then the radical surgical procedure. To date, 37 patients, classified stage III by the international system, have been treated with a 3 yr. survival rate of 74%. The primary purpose of this paper is to present the findings of histopathological examinations of the resected tissues. The laryngeal and neck specimens removed at operation were subjected to processing with celloidin for serial section study. This study so far strongly suggests that the clinical appearance of a larynx after exposure to therapeutic levels of irradiation is a poor indicator of whether or not that larynx harbo]rs residual cancer. In most cases the residual cancer nests were too small to be seenby the naked eye. Cancer remnants were found underlying intact mucous membrane. In the large majority of instances a period of observation will only serve to allow a new generation of cancer cells to develop and thereby might negate the therapeutic effectiveness of radiation. It was observed that squamous cell carci-noam in the larynx undergoes regression into small cancer islands distributed at random in the tumor bed. Any treatment program which depends uponbiopsy of radiated tissue to determine the limits of resection inevit-ablywillhavea high percentage of recurrences. It is not uncommon to observe both areas of cancer-free tissue in the tumor bed and cancer islands close to the preradiation tumor margins. Destroyed cancer cells elicited a foreignbody giant cell reaction with subsequent replacement of giant cells by connective tissue. An atypical hyperplasia of the mucosa of larynges in areas not involved with cancer, particularly in the ventricles, was described. This was an intriguing finding and its significance is being explored. Of 3 neck specimens which were considered positive before and after radiation, 2 were found to be free from cancer on serial section study of every tenth slide. The problem of determining cell viability of irradiated tissue was discussed briefly. The present criteria relied on details of nuclear morphology. A histochemical approach to this problem was discussed.