The Three Vocal Fold Sign in Laryngology

Nupur K Nerurkar¹ https://orcid.org/0000-0002-4127-1590, Gati K Shah², Achala Kamath³

^1-3Department of Voice and Swallowing, Bombay Hospital and Medical Research Center, Mumbai, Maharashtra, India

Corresponding Author: Nupur K Nerurkar, Department of Voice and Swallowing, Bombay Hospital and Medical Research Centre, Mumbai, Maharashtra, India, Phone: +91 9167880256, e-mail: nupurkapoor@yahoo.com

Received on: 06 November 2022; Accepted on: 08 May 2023; Published on: 30 June 2023

ABSTRACT

We are proposing a sign called, “three vocal fold sign” seen on laryngoscopy, which intends to help with the diagnosis of a few clinically challenging conditions like amyloidosis and other granulomatous conditions, laryngopharyngeal reflux, and laryngeal malignancy. This sign is defined as a uniform subepithelial bulge of the undersurface of the vocal folds. This bulge gives an impression of a third vocal fold, the first being the false vocal fold followed by the true vocal fold. A suspicion of amyloidosis or malignancy based on the proposed sign seen on laryngoscopy warrants a contrast-enhanced computed tomography (CT) scan. Any enhancement in the infraglottic region would suggest a possibility of a lesion warranting histopathological confirmation.

How to cite this article: Nerurkar NK, Shah GK, Kamath A. The Three Vocal Fold Sign in Laryngology. Int J Phonosurg Laryngol 2023;13(1):14-15.

Source of support: Nil

Conflict of interest: Dr Nupur K Nerurkar is associated as the National Advisory Board member of this journal and this manuscript was subjected to this journal’s standard review procedures, with this peer review handled independently of this editorial board member and her research group.

Keywords: Granulomatous inflammation, Infraglottis, Laryngeal amyloidosis, Laryngeal cancer, Laryngopharyngeal reflux, Pseudosulcus, Subepithelial bulge.

We propose a new sign, named the “three vocal fold sign,” which can be observed during laryngoscopy when there is a uniform subepithelial bulge of the undersurface of the vocal folds. This bulge creates an impression of a third vocal fold, with the first being the false vocal fold, followed by the true vocal fold (Fig. 1). Koufman¹ described the pseudosulcus of the vocal fold as a laryngoscopic finding for gastroesophageal reflux disease, which is essentially thought to represent infraglottic edema, giving the appearance of a furrow or sulcus subglottically. In contrast, a true sulcus vocalis is characterized by a sulcus at the free edge of the vocal fold that terminates at the vocal process (Fig. 2).

Fig. 1: The proposed “three vocal fold sign”

Fig. 2: True sulcus vocalis

The division of the larynx into anatomical and functional compartments is a topic of debate in the literature. The traditional classification of the larynx includes three compartments—supraglottis, glottis, and subglottis. However, there is no consensus on the superior border of subglottis. The term “subglottis” is used interchangeably with “infraglottis” in many places. Jahnke’s description² includes the laryngeal surface of the epiglottis, arytenoid cartilages, aryepiglottic folds, vestibular folds, and ventricle in the supraglottic region. The glottic region comprises the vocal process of each arytenoid cartilage, vocal folds, and anterior as well as posterior commissure of the vocal cords. The subglottis is bounded inferiorly by the lower boundary of the cricoid cartilage. The superior border of subglottis lacks a universal definition and is typically described as cylindrical in shape. It is bounded superiorly by an imaginary circle 5 mm beneath the free margins of the vocal folds.³ Stell⁴ suggests involving the undersurface of vocal folds in the subglottis, whereas Shaha and Shah⁵ suggest that the subglottic region starts 5 mm underneath the free border of the vocal fold and goes up to the inferior part of the mucosa covering the cricoid cartilage. In contrast, Laramore⁶ states that subglottis begins 1 cm below the true vocal folds.

The most common differential diagnoses for the “three vocal fold sign” are the classical pseudosulcus seen in laryngopharyngeal reflux and occasionally chronic granulomatous diseases such as amyloidosis and infrequently laryngeal malignancy. If amyloidosis or malignancy is suspected based on the proposed sign seen on laryngoscopy, a contrast-enhanced computed tomography (CT) scan with fine 1 mm cuts through the false vocal folds to the subglottis should be performed. Any enhancement in the infraglottic region suggests the possibility of a lesion that warrants histopathological confirmation (Figs 3A and B). The proposed sign seen in laryngopharyngeal reflux (Fig. 4) is assumed to be caused by direct injury from gastric acid reflux, but this remains unproven.

Figs 3A and B: CT scan showing enhancement in infraglottis suggestive of a pathology

Fig. 4: The proposed “three vocal fold sign” in a case of laryngopharyngeal reflux

Therefore, the “three vocal fold sign” on diagnostic laryngoscopy points toward important and otherwise difficult-to-diagnose conditions like granulomatous conditions that is, amyloidosis (Fig. 5) and malignancy.

Fig. 5: The proposed “three vocal fold sign” seen intraoperatively in a case of amyloidosis

ORCID

Nupur K Nerurkar https://orcid.org/0000-0002-4127-1590

REFERENCES

1. Koufman JA. Gastroesophageal reflux and voice disorders. In: Rubin, Sataloff, Korovin, Gould, eds. Diagnosis and Treatment of Voice Disorders. New York-Tokyo: Igaku-Shoin Publishers, 1995:161–175.

2. Jahnke, V. Bösartige tumoren des larynx. In Oto-Rhino-Laryngologie in Klinik und Praxis, Vol. 3. Herberhold C. (ed.). Stuttgart: Thieme, 1995:pp. 388–421.

3. Sessions DG, Ogura JH, Fried MP. Carcinoma of the subglottic area. Laryngoscope 1975;85(10):1417–1423.

4. Stell PM. The subglottic space. Can J Otolaryngol 1975;4(4):674–678. PMID: 1192286.

5. Shaha AR, Shah JP. Carcinoma of the subglottic larynx. Am J Surg 1982;144(4):456–458. DOI: 10.1016/0002-9610(82)90422-6

6. Laramore GE. Larynx. In: Laramore GE (ed) Radiation therapy of head and neck cancer. Springer, Berlin Heidelberg New York, 1989:pp. 125–143.

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