Introduction

Vocal disorders are characterized by deviations that compromise intelligibility and effectiveness of oral communication, among which we may include vocal quality, frequency and intensity alterations, caused by laryngeal, respiratory and/or vocal tract disorders14.

Benign lesions that affect the vocal tract, especially the vocal folds, are common and produce general symptomatology known as dysphonia 6. More than 50% of the people with vocal complaints present benign alterations of vocal fold mucosa1.

Brodnitz (1963) reported a 45% incidence of nodules, polyps and Reinke's edema in a population of 977 subjects. Kleinsasser (1979) reported that more than 50% of the 2,618 patients had one of these diagnostic entities.

Ramig & Verdolini (1998) referred to the occurrence of vocal disorders in the children, adult and elderly populations as respectively from 3-6% to 23.4%, 3 to 9% and 12 to 35%. The authors emphasized that in subjects who make critical use of the voice at work, the incidence of vocal disorders may reach 25%. The importance of voice is so significant that 3.29% of working subjects depend on it to promote public security.

People with dysphonia feel that vocal problems affect negatively their social status and emotional stability. Voice reflects characteristics of personality of the speaker, and for this reason, vocal disorders may have devastating effects on subjects of all ages14.

There are few studies in the literature about the real incidence of different laryngeal benign lesions and most of them are series representing surgical findings of laryngeal microsurgery3, 5, 12.
The present study was carried out aiming at investigating the incidence of non-neoplasic lesions in patients with vocal complaints treated at Hospital do Servidor Público do Estado de São Paulo - Francisco Morato de Oliveira, from March 1999 to March 2000. We carried out incidence analysis by age, gender and type of lesion, its isolated and associated occurrence and the presence of suggestive signs of gastroesophageal reflux.

MATERIAL AND METHOD

Material

We reevaluated videolaryngoscopies, without stroboscopy, conducted at Hospital do Servidor Público do Estado de São Paulo, between March 1999 and March 2000, of patients with vocal complaints. The sample consisted of 1,093 exams, divided into 131 male patients and 962 female patients, ages ranging from 4 to 80 years, mean age of 42.5 years.

Exams were carried out by physicians of the Division of Laryngology at the Service of Otorhinolaryngology. Clinical diagnoses were based on visual impression of lesion. Vocal nodules were classified as exophitic bilateral masses, with symmetric location but no symmetric size, more or less flexible, with some mobility during vocal emission. Vocal cyst, on the other hand, is an intra-cordal lesion, uni or bilateral, which can be asymmetrical in localization and size, more rigid and with less mobility during vocal emission.

Type of lesion was analyzed, if isolated or associated, type of glottic coaptation and presence of suggestive signs of gastroesophageal reflux. In this evaluation the following were considered suggestive signs: retrocricoid edema, interarytenoid mucosa thickness, hyperemia of the arytenoid cartilage region, ulcer and/or posterior granuloma.

We used the following devices to perform videolaryngoscopy:
- 7.0 mm rigid laryngeal telescope at 70º (RICHARDS WOLF);
- 3.2mm flexible nasofibrolaryngoscope (OLYMPUS ENF Type P3);
- light source Hi-light 250 watts (RICHARDS, SMITH +NEPHEW);
- micro-camera (RICHARDS WOLF, 5511 1CCD ENDOCAM);
- videocassette (SEMP, X682);
- video monitor (SONY HR, TRINITON PVM 145 3MD);
- microphone (LENON ML8).

Videolaryngoscopic examinations were carried out under topical anesthesia with 10% lidocaine and we used the telescope in patients that collaborated in the exam and nasofibroscope in the others. Exams were recorded in VCR.

Results

Distribution of 1,093 exams as to age and gender of patients and the other variables is found in Table 1. We identified 13 laryngeal alterations, as follows: 24% Reinke's edema, 10%; vocal sulcus, 10%; vocal nodule, 8%; nodular lesion, 8%; polyp, 7%; vasculodysgenesia, 4%; vocal fold paralysis, 3%; laryngitis, 3%; leukoplasia, 2%; granuloma, 2%; anterior microweb, 1%; mucosa bridge, <1%. The exam was considered normal in 18% of the assessments.

Findings of patients who had different types of alterations are shown in Tables 2 to 11.
The presence of mucosal bridge was identified in only 1 out of 1,093 patients, a male case. The lesion was associated with bilateral corditis, left vocal fold pocket sulcus and right vocal fold cyst, associated to an irregular glottic chink, with no suggestive signs of gastroesophageal reflux.




DISCUSSION

The incidence of each of the benign vocal fold lesions has been poorly described in the literature. Most of the studies report series of surgical findings, which does not represent the real clinical incidence, since the nodule has restrictive surgical indications3, 5, 12.

Bouchayer et al. (1988) presented the following findings in a series of 1,283 lesions of patients submitted to laryngeal microsurgery: nodules, 24%; cyst, 17% (14% epidermic, 3% retention); vocal sulcus, 12%; polyp, 11%; pseudocyst, 6%; Reinke's edema, 6%; nodular lesion, 5%; chronic laryngitis, 4%; postoperative scar, 3%; anterior microweb, 3%; granuloma, 1%; laryngeal papillomatosis, <1%; other lesions, 7%.

Mossallam et al. (1986), in a series of 106 lesions assessed during surgery, found the following incidence: polyps, 42%; cyst, 18%; Reinke's edema, 14%; nodules, 9%; granuloma, 7%; benign neoplasias, 6%; pre-cancer lesions, 4%.

Herrington-Hall et al. (1988) conducted a retrospective study with 1,262 patients, evaluated during a period of two years, aimed at assessing the incidence of laryngeal pathologies, associated to gender, age and occupation. They identified 22 laryngeal pathologies. The most frequent ones were: nodules, 21%; edema, 14%; polyp, 11.4%; carcinoma, 9.7%; vocal fold paralysis, 8.1%; laryngitis, 4.2%; leukoplasia, 4.1%; granuloma, 1%; cyst, 1%, normal examination, 7.9%; other, 20%.

Therefore, the literature considers the organic-functional lesions, especially vocal nodules, as the most frequently detected laryngeal lesion with vocal complaints, according to most authors.
Nodules are the main cause of dysphonia among children and adolescents and as from the age of 15 years, it is practically only seen in female patients. Herrington-Hall et al. (1988) reported the highest incidence of nodules in women aged 25 to 44 years.

In our study, nodules were not the most frequent lesion and they were detected in 90 out of 1,093 patients (8%), aged 4 to 66 years, mean age of 34.4 years. We observed higher incidence of female patients (87%). As to glottic closure, 74 patients (82%) presented incomplete coaptation with glottic chink, and the most common type was double chink (37%), followed by middle-posterior triangular chink (28%).

The genesis of vocal nodule is multifactorial, involving predisposing anatomic factors, personality characteristics, and inappropriate vocal behavior. Among anatomic factors, we highlight the presence of middle-posterior triangular chink in whose vertex the vibration energy is concentrated during phonation, responsible for tissue thickness. Double chinks, in fact, are middle-posterior triangular chinks with mucosa lesion, predominantly localized edema, uni or bilateral, which produced the onset of anterior opening. Since chinks normally result from association of female pattern of glottic proportion with the syndrome of muscle tension, nodules present higher incidence in women and children2.

The most common lesion in our study was vocal cyst, found in 267 patients (24%), aged from 10 to 80 years, mean age of 40 years. Female gender was predominant with 97% of the cases. In 84% of the patients, the lesion was isolated and in 16% it was associated, and vasculodysgenesia was the most common associated pathology in such cases (80%). We observed glottic chink in 58.8% of the cases, and hourglass chinks were the most common ones, present in 29% of the patients.

Cysts are minimal structural alterations of the lining of the vocal folds, representing a structural disarrangement that takes place at embryogenesis and is manifested at any age, normally triggered by intensive or abusive vocal use.

Cysts in the study by Mossallam et al. (1986) and Bouchayer et al. (1988) were the second most frequent lesions. Herrington-Hall et al. (1988) diagnosed cysts in only 12 out of 1,262 dysphonic patients (1%), predominantly in the age range of 45 to 64 years, 7 men and 5 women. Methodological differences can probably explain the discrepancy in results from one study to the other.

Reinke's edema was the second most frequent lesion in our study, present in 113 patients (10%). Mossallam et al. (1986) found an incidence of 14%, whereas Bouchayer et al. detected 6%. Ages ranged from 26 to 76 years, mean age of 51 years, more common in women (96%), in accordance with the literature that also reported higher prevalence of the pathology in female subjects. Only 17% had associated lesions, and leukoplasia was the most common one (35%). We found incomplete coaptation in 32%, with irregular chink in most cases (25%), as expected by the characteristics of this mass lesion. Herrington-Hall et al. (1988) found edema in 272 out of 1,262 patients (14.1%), with predominance of female patients in the age range of 25 to 44 years, followed by the age range 45 to 64 years.

Vocal sulcus was found in 110 patients (10%). Bouchayer et al. (1988) analyzed 1,283 patients and found a 12% incidence of vocal sulcus, close to our own results. The identification of this lesion, similarly to vocal cysts, depends on the knowledge of the examiner about the pathologies and their characteristics2, 7.

Polyps were found in 7% of the patients, ages ranging from 20 to 77 years, mean age of 45 years, more common in women (83%), differently from the findings of other authors who considered this lesion a male characteristic. Kleinsasser (1982), in Hall et al. (1988), in a review of 900 cases of vocal fold polyps, found a predominance in male patients (76%), mean age of 40 years in men and 38 years in women.

We observed vasculodysgenesia in 4% of the patients, and in 76% of them they were isolated lesions, which did not correspond to literature findings, because this lesion has rarely been identified as isolated3, 6, 12.

Vocal fold paralyses are responsible for 3% of the cases of dysphonia, with higher incidence of patients, mean age of 55 years, as reported by the authors. Herrington-Hall et al. (1988) found an incidence of 8.1% of paralysis, predominantly in older patients, aged 64 years.

Leukoplasia was identified in 17 patients (2%), mean age of 54 years, with no significant difference concerning gender (9 men to 8 women), disagreeing from most of the authors that reported higher incidence among male subjects. Herrington-Hall et al. (1988) found an incidence of leukoplasia of 4.1%, predominance of male gender and age range 45 to 64 years.

Granuloma was found in 18 patients (2%), mean age of 40 years, predominance of female gender (78%), differently from the literature data, in which the most frequently found lesion in male was granuloma. Bouchayer et al. (1988) and Herrington-Hall et al. (1988) found an incidence of 1%, whereas Mossallam et al. (1986) mentioned an incidence of 7%. Lehmann and Widman (1986) analyzed a series of 1,300 patients with dysphonia and found an incidence of granuloma of 5%, mean age of 44 years.

Anterior microweb, in turn, was identified in 10 patients (<1%). Bouchayer et al. (1988) found a 3% incidence. In 80% of the cases in our study, the lesion was associated with another pathology, normally vocal cysts. These data do not correlate to the literature, which frequently reported joint occurrence of anterior microweb and leukoplasia or vocal nodules.

As to suggestive presence of gastroesophageal reflux, the group that presented a higher incidence was that of patients with diagnosis of leukoplasia - 53%; followed by vasculodysgenesia, 50%; granuloma, 39%; edema, 35%; sulcus, 31%; polyp, 27%; nodule, 26% and cyst, 23%. Classically, gastroesophageal reflux is more commonly related to laryngitis and posterior laryngeal granuloma. Ohmann et al. (1983) detected a 74% incidence of gastroesophageal reflux in patients with vocal fold granuloma as opposed to 30% in the general population. However, Lehmann & Widman (1986) identified gastroesophageal reflux in only 1 case out of 32 patients with contact granuloma. Gastroesophageal reflux is still associated with laryngeal and tracheal stenosis, laryngospasms, asthma, infant sudden death syndrome, laryngomalacia, bronchopulmonary dysplasia and aspiration pneumonia.

Conclusion

Based on the results of the present study, analyzing videolaryngoscopic examinations of 1,093 patients treated between March 1999 and March 2000, we concluded that the most frequent laryngeal lesion in patients with vocal complaints was cyst, classified as a minimal structural alteration of vocal fold lining, resulting in functional dysphonia. These data were differently from most authors3, 8, 12, who reported organic-functional lesions (nodules, polyps and Reinke's edema) as the most common lesions.

References

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11. LEHMAN, W.; WIDMAN, J. J. - Nonspecific granulomas of the larynx. In KIRCHNER, J.A. (ed.) Vocal Fold Histopathology: A Symposium. San Diego, College-Hill, pp. 97-107, 1986.
12. MOSSALLAM, I.; KOTBY, M. N.; GHALY, A. F. et al. - Histopathological aspects of benign vocal fold lesions associated with dysphonia. In KIRCHNER, J.A. (ed.) Vocal Fold histiopathology: A symposium. San Diego, College-Hill, pp. 65-80, 1986.
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1 Resident Physician, Service of Otorhinolaryngology, Hospital do Servidor Público Estadual de São Paulo / FMO
2 Head of the Division of Head and Neck Surgery, Service of Otorhinolaryngology, Hospital do Servidor Público Estadual de São Paulo / FMO; Ph.D. in Medicine, Escola Paulista de Medicina - Unifesp
3 Speech therapist; Ph.D. in Science, Universidade Federal de São Paulo - EPM; Director of Centro de Estudos da Voz - CEV, São Paulo
4 Undergraduate, Course of Speech and Hearing Therapy, Centro Paraibano de Educação

Hospital do Servidor Público Estadual de São Paulo / Francisco Morato de Oliveira - São Paulo - SP
Address correspondence to: Erich Christiano Madruga de Melo - R. Borges Lagoa, 1565 Apto. 10 - Vila Clementino - São Paulo - SP - 04038-034 - E-mail: erichmelo@uol.com.br
Article submitted on April 03, 2001. Article accepted on April 27, 2001.