The role of contact endoscopy in screening for premalignant laryngeal lesions: a study of 141 patients.

At their earliest stage, pathologic lesions of the laryngeal epithelium are macroscopically invisible. Ideally, these lesions should he detected before their clinical manifestations appear so that prompt management can be initiated. However, most diagnostic modalities are unable to detect early premalignant lesions. We conducted a retrospective study of the use of contact endoscopy in analyzing the vocal fold mucosal epithelium in adults who had been operated on at our hospital under general anesthesia for various nonlaryngeal diseases. After we identified 71 such patients who were smokers, we chose an almost equal number of nonsmokers (n 70) for comparison purposes. In all, our study population was made up of 141 patients—51 men and 90 women, aged 21 to 78 years (mean: 52). All patients had normal findings onpreoperative laryngeal endoscopy. Our goal was to determine if the routine use of this diagnostic modality is justified in selected cases. Contact endoscopy identified dysplastic vocal fold lesions in 4 patients and chronic laryngitis in 3; all 7 of these patients were smokers. Since early laryngeal lesions are not macroscopically evident, early detection ofthese changes by other means is associated with a better prognosis and easier management. Our study demonstrates that the use of contact endoscopy during general anesthesia as a standard diagnostic method in long-time cigarette smokers is fully justified. Introduction Even the mildest abnormality of the vocal folds can lead to hoarseness. Ideally, changes in the vocal fold From the University Department of ENT-Head and Neck Surgery, Split University Hospital Center, Split, Croatia. Corresponding author: Drasko Cikojevic, MD, PhD, University Department of ENT-Head and Neck Surgery, Split University Hospital Center, Spinciceva 1, HR-21000 Split, Croatia. Email: drasko. cikojevic@st.t-com.hr mucosa will be detected early on, before they manifest clinically. One diagnostic modality that is useful in this regard is contact endoscopy. This noninvasive method provides an insight into the microscopic picture of laryngeal mucosa epithelium. With this simple and noninvasive method, cells are analyzed in vivo, thus avoiding the possibility of cell damage and distortion. Contact endoscopy was first described by Hamou et al in 1984 in a gynecologic diagnosis.' In the 1990s, Andrea et al reported the use of contact endoscopy in examining the vocal folds^ and the nasal mucosa.' Arens et al" confirmed the efficacy of contact endoscopy in examining the larynx, and Cikojevic et aP demonstrated that it was superior to frozen-section histopathology in diagnosing laryngeal pathology. These and other studies* ' have shown that contact endoscopy is a reliable method in the diagnosis of malignant and premalignant diseases. In this article, we describe our study of contact endoscopy in examining the epithelium of the vocal fold mucosa in smokers and nonsmokers who were free of clinical symptoms of laryngeal disease. Patients and methods For this retrospective study, we studied the use of contact endoscopy to analyze the mucosal epithelium of the vocal folds of 71 smokers who were operated on at our hospital under general anesthesia for the treatment of various nonlaryngeal diseases. For comparison purposes, we chose an almost equal number of nonsmokers (n = 70) who had undergone the same type of procedures. In all, our study population was made up of 141 patients—51 men and 90 women, aged 21 to 78 years (mean: 52). Indications for surgery included thyroid disease, nasal septal deviation, nasal polyposis, cervical cysts, and other conditions. All patients had normal findings on preoperative laryngeal endoscopy. Volume 93, Number 4-5 www.entjournal.com • 177 KlANONIK, GLUNOIO, CIKOJEVIO Figure 1. Contact endoscopy shows normal vocal fold epithelium (original magniftcation x60). Upon induction of endotracheal anesthesia, the vocal fold mucosa was stained with 1% methylene blue. After 1 minute, a contact endoscope was placed against the vocal fold and moved along it from the anterior commissure toward the posterior aspect. The examination was captured on video. This was done on both vocal folds. A pathologist later analyzed the video images. A biopsy for histopathology was not routinely performed during the procedure; however, a biopsy was subsequently recommended for those patients who were found to have a pathologic lesion. Findings on contact endoscopy were classified into four categories: normal mucosa, chronic laryngitis, dysplasia, and squamous cell carcinoma: Normal mucosa. The stratified squamous epithelial cells are homogeneously distributed. The nuclei are small, pyknotic, and dark blue, and the cytoplasm is large and light blue (figure 1). Chronic laryngitis. Cells are homogeneously distributed. The nuclei are slightly enlarged, and they have rounded edges. There might be slight hyperchromatism, but chromatin is uniformly and finely granulated and free of maj or chromatin abnormalities (figure 2). Dysplasia. The cell population is heterogeneous. The nuclei are enlarged, variedly shaped, and hyperchromatic. The nucleus-to-cytoplasm ratio is weighted in favor of the nucleus. There is an increase in the number of mitoses, and dyskaryosis, anisokaryosis, and dyschromatosis are present (figure 3). Squamous cell carcinoma. There is a pronounced heterogeneity of the cell population. Nuclear hyperchromatism and an irregular chromatin distribution Figure 2. This view shows chronic laryngitis with regular microvasculature of the vocal fold (original magniftcation x60). are seen, and there is an increase in the size and number of irregularly shaped nuclei. The nucleusto-cytoplasm ratio is tilted in favor of the nucleus. Our study was approved by our hospital's Ethics Committee, and written informed consent was obtained from all patients. Results Contact endoscopy detected abnormal findings in 7 of the 71 smokers (9.9%) and in none of the nonsmokers. Four smokers had a dysplastic vocal fold lesion (1 grade I lesion and 3 grade II lesions) and 3 had chronic laryngitis. A higher incidence of premalignant pathology was associated with a greater number of cigarettes per day. No pathologic lesions were observed in 21 patients who smoked 10 or fewer cigarettes per day (table 1). Figure 3. This view shows dysplasia (original magniftcation xl50). 178 • www.entjournal.com ENT-Ear, Nose & Throat Journal • April/May 2014 THE ROLE OF CONTACT ENDOSCOPY IN SCREENING FOR PREMALIGNANT LARYNGEAL LESIONS: A STUDY OF 141 PATIENTS Table 1. Correlation