Comparative Study of Fine Needle Aspiration Cytology and Histopathology Results of Salivary Gland Swelling in St. Paul’s Hospital Millennium Medical College, Addis Ababa, Ethiopia

Mohammed Sefa Arusi Dari^1*, Zeyneb Saleh Hassen² and Zelalem Tadesse Wondimu³

¹Department of Otolaryngology Head and Neck Surgery, Addis Ababa University, Addis Ababa, Ethiopia

²General Practitioner, St. Paul Hospital Millennium Medical College, Addis Ababa, Ethiopia

³Department of Internal Medicine, Wolkite University, Wolkite, Ethiopia

^*Corresponding author: Mohammed Sefa Arusi Dari, Department of Otolaryngology Head and Neck Surgery, Addis Ababa University, Addis Ababa, Ethiopia, E-mail: [email protected]

Received: February 01, 2025, Accepted: February 17, 2025, Published: March 19, 2025

Citation: Mohammed Sefa Arusi Dari. Comparative Study of Fine Needle Aspiration Cytology and Histopathology Results of Salivary Gland Swelling in St. Paul’s Hospital Millennium Medical College, Addis Ababa, Ethiopia. World J Surg Surgical Case Rep. 2025;1(1): 1-17.

Copyright: ©2025 Mohammed Sefa Arusi Dari. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract

Background: Fine-Needle Aspiration Cytology (FNAC) is a widely accepted, safe, and cost-effective diagnostic tool for evaluating salivary gland swellings. It helps differentiate between benign, inflammatory, and malignant lesions, aiding in surgical planning and management.

Objective: This study aimed to compare FNAC results with histopathology findings to assess the diagnostic accuracy of FNAC in evaluating salivary gland swellings at St. Paul’s Hospital Millennium Medical College, Addis Ababa, Ethiopia.

Methods: A four-year hospital-based cross-sectional study was conducted on patients with salivary gland swellings who underwent both FNAC and histopathology at St. Paul’s Hospital Millennium Medical College from January 1, 2019, to August 30, 2022. Data were collected using a standardized questionnaire and analyzed using SPSS version 27. Sensitivity, specificity, Positive Predictive Value (PPV), Negative Predictive Value (NPV), and accuracy were calculated using histopathology as the gold standard.

Results: Of the 475 FNACs performed, 110 cases had correlating histopathology results. The parotid gland was the most commonly affected site (46.4%), followed by the submandibular gland (42.7%) and minor salivary glands (10.9%). FNAC demonstrated high sensitivity, specificity, and accuracy: 100%, 98.83%, and 99.09% for non-neoplastic lesions; 96.4%, 92.6%, and 94.5% for benign neoplasms; and 83.3%, 95.5%, and 94.54% for malignant neoplasms, respectively.

Conclusion: FNAC is a highly sensitive and specific diagnostic tool for evaluating salivary gland swellings. It is reliable for preoperative planning and can help avoid unnecessary surgical interventions.

Keywords: Salivary gland, Fine needle aspiration cytology, Histopathology, Diagnostic accuracy

1. Introduction

1.1. Background of the study

Salivary gland swellings can result from tumors, inflammatory processes, or cysts. Salivary gland tumors account for approximately 3% of all head and neck malignancies, with the majority of these neoplasms being benign^1,2. Malignant salivary gland tumors represent only 20% of cases, and the annual incidence of salivary gland cancers is reported to be 0.5 to 2 per 100,000 people. These tumors affect both men and women equally, with the majority of cases occurring in the sixth decade of life³. Tumors can develop in both the major and minor salivary glands, with the parotid glands accounting for 80% of major salivary gland tumors, while the palate is the most common site for minor salivary gland tumors⁴.

Clinical practice has shown that the smaller the salivary gland, the more likely the tumor is malignant. Around 20% to 25% of tumors in the parotid glands are malignant, while this percentage increases to 40% in the submandibular glands, and over 90% of sublingual gland tumors are malignant^3,5. The parotid gland accounts for 75% of salivary gland tumors, while the submandibular glands contribute 25%. Minor salivary glands and the sublingual glands account for 8% and 1%, respectively. The most common benign tumor is pleomorphic adenoma, which is predominantly of parotid gland origin. Among malignant tumors, mucoepidermoid carcinoma is the most common, while adenoid cystic carcinoma is the most common malignant tumor in the submandibular and minor salivary glands⁶.

Non-neoplastic lesions of the salivary glands are often caused by chronic sialadenitis, followed by retention cysts. Salivary gland cystic abnormalities can be classified as either true cysts (e.g., lymphoepithelial cysts) or non-developmental cysts (e.g., retention cysts)^7,8.

Fine Needle Aspiration Cytology (FNAC) has proven to be an efficient, simple, and safe method for evaluating salivary gland enlargement. FNAC boasts high sensitivity, specificity, and accuracy in identifying salivary gland lesions^1,2. The sensitivity of FNAC for salivary gland lesions ranges from 86% to 100%, while specificity ranges from 90% to 100%⁸. The accuracy of FNAC is highly dependent on the experience of both the pathologist and the clinician performing the aspiration¹. FNAC is crucial in treatment planning, as it allows clinicians to avoid unnecessary surgeries and reduces healthcare costs⁹. While open biopsy may provide diagnostic information, it is generally avoided due to its invasiveness, which can complicate subsequent surgical interventions¹⁰.

1.2. Statement of the problem

Salivary gland swellings represent a diverse and challenging group of disorders with variable clinical presentations, making accurate diagnosis essential¹. While Fine-Needle Aspiration Cytology (FNAC) is widely used for the preoperative evaluation of head and neck tumors, its accuracy in diagnosing salivary gland masses remains debated in comparison to other diagnostic modalities. FNAC is a commonly performed, safe, and typically well-tolerated procedure that provides valuable diagnostic information. The primary goal of FNAC in salivary gland swelling is to distinguish between inflammatory and reactive processes, identify benign versus malignant neoplasms, and provide a definitive diagnosis when possible.

The accuracy of FNAC significantly impacts the surgical management of salivary gland swellings. It has been suggested that preoperative FNAC results play a key role in determining the management strategy for salivary gland swellings, including the decision to proceed with surgery. Knowing whether a lesion is malignant or benign in advance can help clinicians tailor surgical approaches, which could potentially delay or expedite intervention. Despite the unknown prevalence of salivary gland swellings in our region, many patients with these swellings present to our institution for diagnosis and management. Given the limited access to advanced imaging modalities such as CT or MRI, clinicians rely heavily on FNAC and clinical examination to guide their decisions. This study aims to correlate FNAC diagnoses with histopathology and assess the sensitivity and specificity of FNAC in diagnosing salivary gland swellings in our institution.

1.3. General objective

The general objective of this study is to compare the FNAC results with histopathology findings of salivary gland swellings in order to assess its diagnostic accuracy among patients who had both FNAC and histopathology results at Saint Paul’s Hospital Millennium Medical College, Department of ORL HNS, and the Oral and Maxillofacial Surgery Department in Addis Ababa, Ethiopia, from January 1, 2019, to August 30, 2022, G.C.

1.4. Specific objectives

The specific objectives of this study are as follows:

·       To determine the accuracy of FNAC diagnosis of salivary gland swelling when compared with histopathology.

·       To evaluate the sensitivity and specificity of FNAC in diagnosing salivary gland swellings in our institution.

·       To identify the patterns of etiology of salivary gland swellings in our institution.