Introduction

The larynx is an endogenous anatomical structure that serves a multifaceted purpose, including safeguarding, breathing, and vocalisation. In order to perform its intended role, it is necessary for the larynx to possess adaptability and flexibility. The proper configuration of the vocal cord's structure is crucial for speech production. This structure comprises the epithelium and lamina propria of a vocal ligament, with particular emphasis on the superficial layer, also known as Reinke's space. This layer is of utmost importance as it represents a potential space with minimal subepithelial connective tissue, as documented in literature [1].

Laryngeal lesions encompass a range of conditions, including non-cancerous growths on the vocal cords, as well as potentially cancerous growths that may be either precursors to malignancy or fully malignant in nature. The prevalent benign laryngeal lesions are vocal nodules and polyps. These are typically identified through patient history, clinical complaints, and visual examination techniques, such as indirect laryngoscopy with rigid or flexible fibre optic scope and stroboscopy [2]. Hoarseness is a prevalent laryngeal symptom that prompts patients to seek treatment in the field of otolaryngology. This condition can be attributed to a range of potential disorders.

Currently, the diagnostic process for laryngeal diseases in clinical settings is intricate and relies on the assessment of patients' symptoms, medical history, and results from instrumental and histological examinations. Over the past 20 years, numerous imaging techniques have been developed to examine the larynx and acquire precise measurements of voice quality [3]. Recent research has highlighted the significance of the clinico-histological correlation in laryngeal pathologies. Therefore, it is imperative to conduct a histological examination in order to ascertain the characteristics of laryngeal lesions and determine subsequent management strategies.

Materials and Methods

The present investigation was carried out at the Department of Otorhinolaryngology situated in Chettinad Hospital and Research Institute. The study was conducted in accordance with the guidelines set forth by the Institutional Human Ethical Committee and spanned from February 2022 to April 2023. The research encompassed a cohort of 80 specimens comprising individuals who received surgical intervention for laryngeal lesions. Following the acquisition of informed consent from the participants, a histopathological analysis was conducted on each sample. This was achieved by initially fixing the samples with buffered formalin (10%). Hematoxylin and eosin stains were utilised for the examination, and for certain cases, an immunohistochemical study was conducted. The pertinent clinical information was extracted from the case files. The slides were gathered and subjected to analysis to investigate diverse clinicopathological manifestations of laryngeal lesions.

Results

The findings of our study indicate a higher prevalence of the condition among males as compared to females, with a male to female ratio of 1.17:1. Regarding the patients' professions, 27 individuals identified as housewives, 7 individuals identified as teachers, and 4 individuals identified as singers. Furthermore, the study revealed that 38 (47.5%) of the patients were identified as smokers, while the remaining 42 (52.5%) were classified as non-smokers. The prevalent grievance among 72 patients (90%) is the manifestation of hoarseness in their vocal quality. The study revealed that a significant proportion of patients experienced various complaints, such as Dysphagia in 36 patients (45%), Dyspnoea in 25 patients (31.25%), Odynophagia in 10 patients (12.05%), Aspiration in 2 patients (2.5%), and hemoptysis in 1 patient (1.02%).

Out of a cohort of 80 patients, 46.25% (n=37) presented with non-neoplastic lesions, while 53.75% (n=43) were diagnosed with neoplastic lesions. The study revealed that among the 37 non-neoplastic lesions, vocal cord polyp was the most frequently occurring lesion, with a prevalence of 48.64% among the patients (as presented in Table 1). Similarly, among the 43 neoplastic lesions, squamous cell carcinoma was found to be the most prevalent lesion, with a prevalence of 74.41% among the patients (as presented in Table 2).

A polyp of the vocal cord is a pedunculated mass that is round and circumscribed, and it develops along the membranous portion of the vocal cord. The histological presentation of the subject matter may manifest in gelatinous, telangiectatic, or hyaline form. The lamina propria exhibits alterations in its vasculature, deposition of amorphous material, and evidence of prior hemorrhagic events, as depicted in Figure 1.

Fig. 1: Vocal cord polyp

Vocal cord nodules are non-malignant, greyish-white, and firm protrusions that are located along the unattached edge of the vocal cords. It typically manifests at the intersection of the anterior one-third and posterior two-thirds. Females are more frequently impacted by voice misuse and improper vocal technique. The histopathological examination reveals the presence of submucosal edema and haemorrhage, which subsequently undergo hyalinization and fibrosis. The formation of a nodule can be observed as a result of hyperplasia of the overlying epithelium (refer to Fig. 2).

Fig 2: Vocal cord nodule

Keratosis refers to the presence of a white plaque or warty growth on the upper surface of one or both vocal cords, which is attributed to prolonged exposure to irritants. The aforementioned is a lesion that has the potential to develop into cancer. Epithelial hyperplasia will be observed at a microscopic level, as depicted in Figure 3.

Fig. 3: Keratosis

Vocal cord cysts are non-malignant growths that manifest as a sac-like structure enclosed within the membranous vocal cords. From a histological standpoint, it can be classified into two distinct types: Vocal cord cysts can be classified into two types: subepithelial vocal cord cysts and ligament vocal cord cysts. The former occurs in the superficial lamina propria, while the latter occurs in the deep layers of the propria. The lining of the cyst wall comprises of either squamous epithelial cells or glandular cells, as depicted in Figure 4.

Fig 4: Vocal cord cyst

A benign lesion known as the laryngeal cyst is known to occur within the mucosal layer of the larynx, with a higher incidence in the supraglottic region. This occurrence can result in respiratory distress. From a histological perspective, the entity in question can be classified into five distinct types, namely Ductal (constituting 75% of cases), Saccular (accounting for 24% of cases), and several other subtypes including Laryngocele, Oncocytic cyst, and Tonsillar cyst. The lining of the cyst wall is composed of glandular cells, as depicted in Figure 5.

Fig. 5: Laryngeal cyst

Papilloma is a pathological state that arises due to mucosal infection by human papillomavirus and is considered to be a precursor to malignancy. The male population exhibits a higher incidence rate of the aforementioned condition. The histological features of the condition are distinguished by the presence of papillary proliferation of stratified squamous epithelium, which may exhibit varying degrees of hyperkeratosis or parakeratosis.

Granulations of the vocal cords are infrequent and may present as either unilateral or bilateral rounded lesions of diverse hues, featuring a pedicle and a surface that may be either smooth or uneven. At the microscopic level, the observed features include an undamaged or ulcerated squamous epithelium, accompanied by the growth of fibrous tissue and highly vascularized granulation tissue. Additionally, there is infiltration of lymphocytes and plasma cells, as depicted in Figure 6.

Fig. 6: Granulation tissue

Laryngeal hemangiomas are vascular tumours that exhibit slow progression and are frequently detected in paediatric patients. The pathological analysis reveals the presence of hyperplasia of blood vessels and hemangiectasis beneath the squamous mucosa, accompanied by lymphocyte infiltration surrounding the vessel.

Pleomorphic adenomas are infrequent pathological occurrences observed within the larynx. Typically, the tumour is characterised by a slow growth rate, solitary appearance, and absence of pain. Pleomorphic adenomas are typified by the presence of epithelial tissue intermingled with tissues exhibiting myxoid, mucoid, or chondroid morphologies. The pleomorphic adenoma of the larynx may exhibit similarities to aggressive epithelial tumours in terms of its histological features, owing to its high cellularity and absence of a stromal component, as depicted in Figure 7.

Fig. 7: Pleomorphic adenoma

Squamous cell carcinoma represents the most prevalent form of malignant neoplasm. The examination conducted at a microscopic level reveals the presence of tumour cells that are grouped together in masses or nests, exhibiting squamous differentiation. These groups are characterised by the presence of extracellular keratin pearls, intracellular keratin, and intercellular bridges, as depicted in Figure 8.

Fig. 8: Squamous cell carcinoma

Laryngeal malignancies comprise a minute fraction of adenocarcinomas, constituting less than one percent of the total cases. The tumour tissue exhibited a lobulated morphology and consisted of polygonal epithelial cells, as observed through histological analysis. The cellular entities coalesce into cohesive clusters and configurations reminiscent of acinar formations.

Discussion

Laryngeal neoplasms are typically identified at an early stage as a result of dysphonia, which is characterised by alterations in vocal quality. The most frequently reported symptom in our investigation was hoarseness of voice, with a prevalence of 90%. The prevalence of benign tumours was highest during the third decade of life, while malignant tumours were more frequently observed among individuals aged 61 to 70 years. According to Shirley D and colleagues, there is a positive correlation between age and the incidence of malignant tumours, with the mean age of diagnosis being 66 years [4].

The present study revealed a higher incidence of both benign and malignant lesions in males as compared to females, with a male to female ratio of 1.17:1. These findings are consistent with those reported by Wani et al. The higher prevalence of voice disorders in males may be linked to factors such as occupational hazards, vocal misuse, smoking, and alcohol consumption, as reported in previous studies [5].

Approximately 46.25% of cases were comprised of non-neoplastic lesions, with vocal polyps being the most frequently occurring type. The vocal cord polyp is a discrete, pedunculated lesion that develops along the membranous portion of the vocal cord. The histological presentation of the specimen may exhibit characteristics of either the gelatinous, telangiectatic, or hyaline type. The present study revealed a prevalence of 22.5% of vocal polyp cases, which is higher than the prevalence reported by Chopra et al. (16%) and lower than the prevalence reported by Kavitha Y et al. (31.4%) in their respective studies [6,7].

The second most frequent non-neoplastic lesion observed was vocal cord nodule, which accounted for 13 cases (16.25%). Varalakshmi KP and colleagues reported a prevalence of 8.4% in their study [8]. The study identified additional non-neoplastic lesions, including keratosis, vocal cord cyst, and laryngeal cyst.

The prevalence of neoplastic lesions was found to be 53.75%, with 10% of cases being benign tumours and 43.75% being malignant tumours. Papilloma was found to be the most prevalent type among the benign neoplastic lesions. Papilloma is a pathological state that arises due to mucosal infection by human papillomavirus and is considered to be a precancerous condition. The histological features of this condition are marked by the papillary proliferation of stratified squamous epithelium, which exhibits varying degrees of hyperkeratosis or parakeratosis. The study observed a prevalence of 6.25%, which is consistent with the findings of Chavan SS et al. [9] and Ritu Bhagatet al., who reported a prevalence of 6% and 6.7%, respectively. Our study observed one instance of hemangioma cases, which accounts for 1.25% of the total cases. This finding is consistent with the results reported by Varalakshmi KP et al and Ritu Bhagat et al, who also observed a similar incidence rate of 1.1%.

The most prevalent malignant neoplasm observed was squamous cell carcinoma, accounting for 40% of cases with a total of 32 instances. In their respective studies, Varalakshmi KP et al, Ritu Bhagat et al, and Kavitha Y et al documented prevalence rates of 41.1%, 52.2%, and 36.4% for the condition under investigation. Squamous cell carcinoma frequently originates in a context of mucosal squamous dysplasia or carcinoma in situ. The presentation typically involves the infiltration of the laryngeal stroma by atypical cells in the form of islands, tongues, and clusters. The study reported a prevalence of 3 cases (3.75%) of adenocarcinoma of the larynx, which is higher than the prevalence reported by Varalakshmi KP et al and Ritu Bhagat et al (1.1%) in their respective studies [10].

Conclusion

The manifestation of laryngeal tumours can exhibit a range of severity, from minor changes in vocal quality to critical respiratory compromise [11]. It is imperative to employ all feasible diagnostic techniques to expedite the identification of malignant tumours, given their significantly elevated incidence. The timely detection of a lesion through endoscopic examination and subsequent biopsy can result in successful treatment and significantly enhance the patient's prognosis [12]. Individuals who are considered high-risk, such as elderly males with a smoking history, should be thoroughly assessed with a heightened level of suspicion for the presence of malignant lesions if they exhibit any of these symptoms [13].

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