# Histological, Cytological, and Radiological Correlation in Thyroid Lesions

## TL;DR

This study shows that combining cytology, imaging, and histopathology improves accuracy in diagnosing thyroid lesions, with FNAC and TIRADS being key tools.

## Contribution

The study evaluates the combined diagnostic value of FNAC, TIRADS, and histopathology in thyroid lesions for better clinical decision-making.

## Key findings

- FNAC had 96% diagnostic adequacy, 62.5% sensitivity, and 97.7% specificity in thyroid lesion diagnosis.
- All TIRADS 5 lesions were confirmed malignant on histopathology, showing strong correlation.
- Cytoradiological and cytohistological concordance was high in both benign and malignant categories.

## Abstract

Background: Thyroid disorders are among the most common endocrine diseases, with lesions ranging from benign nodules to malignant neoplasms. Accurate preoperative diagnosis is crucial for appropriate management. Fine-needle aspiration cytology (FNAC) is a widely used diagnostic tool, while ultrasonography (USG) and histopathology provide valuable adjunctive information. Correlating these modalities enhances diagnostic accuracy and clinical decision-making.

Objectives: To evaluate the cytological, histopathological, and radiological correlation in thyroid lesions and determine the diagnostic accuracy of FNAC and Thyroid Imaging Reporting and Data System (TIRADS) in differentiating benign and malignant thyroid nodules.

Methodology: This cross-sectional, observational study was conducted in the Department of Pathology at Gandhi Medical College and Associated Hospitals, Bhopal, from May 2023 to October 2024, following approval of the ethics committee. A total of 150 samples from patients presenting with thyroid swellings were included in the study. All patients underwent clinical evaluation, thyroid function testing, USG (classified using the TIRADS system), and FNAC. Surgical specimens were subjected to histopathological examination wherever available.

Results: The majority of patients were middle-aged females, with a female-to-male ratio of 4.6:1. The majority of lesions were benign, with colloid goiter being the most common diagnosis (40, 26.7%), followed by lymphocytic thyroiditis (17, 11.3%) and nodular goiter (15, 10%). On USG, most nodules were TIRADS 2 (58, 38.7%) and TIRADS 3 (63, 42%), while all TIRADS 5 lesions were malignant on histopathology (P < 0.001). FNAC demonstrated a diagnostic adequacy of 96%, with an overall sensitivity of 62.5%, a specificity of 97.7%, and a diagnostic accuracy of 92.3%. Strong cytoradiological and cytohistological concordance was observed in benign and malignant categories.

Conclusions: The integration of cytological, radiological, and histopathological evaluation significantly improves the diagnostic precision of thyroid lesions. FNAC remains a simple, cost-effective, and reliable first-line investigation, while TIRADS scoring effectively stratifies the risk of malignancy. The combined use of these modalities facilitates accurate diagnosis, rational surgical intervention, and optimal patient management.