A Study on Solitary Nodule of Thyroid Gland: Evaluation of Risk Factors Associated With Occurrence of Malignancy, Diagnostic Modalities and Management at a Tertiary Care Hospital

Abstract

Background: A solitary thyroid nodule is a single, discrete swelling within an otherwise normal thyroid gland, encountered frequently in surgical practice. Although 80–90% of such nodules are benign, a solitary nodule carries a higher individual risk of malignancy (11–20%) than a nodule within a multinodular goitre (~5%), which makes systematic clinical, cytological and histopathological evaluation essential for rational management.

Aim: To study the incidence of malignancy in solitary thyroid nodules, to evaluate the risk factors associated with malignant transformation, and to correlate fine needle aspiration cytology (FNAC) with final histopathological examination (HPE) at a tertiary care teaching hospital.

Methods: This prospective observational study was conducted in the Department of General Surgery at a tertiary care teaching hospital over a two-year period. Seventy-nine patients above 12 years of age with a clinically palpable thyroid swelling who consented to surgical management were enrolled. Detailed history, clinical examination, thyroid function tests, ultrasonography and FNAC were performed in all patients, who subsequently underwent thyroidectomy with histopathological correlation of the resected specimen.

Results: The mean age of presentation was 42.65 ± 13.91 years (range 17–72 years), with marked female preponderance (94.94%; male:female = 1:19). Swelling of more than 24 months' duration was seen in 55.75% of patients. FNAC classified 82.28% of nodules as benign, 10.13% as suspicious of malignancy and 7.69% as suspicious follicular neoplasm. On final histopathology, colloid goitre (72.15%) was the commonest diagnosis, followed by papillary carcinoma (11.39%), lymphocytic thyroiditis (10.13%) and follicular carcinoma (6.33%); no anaplastic carcinoma was recorded. The overall malignancy rate was 17.72%, and FNAC showed a sensitivity of 91.8% and specificity of 98.3% against histopathology.

Conclusion: Solitary thyroid nodules in this cohort predominantly affected middle-aged women and were mostly benign, but nearly one in six harboured malignancy, chiefly papillary carcinoma. FNAC remains a reliable first-line triage tool, but its imperfect sensitivity for follicular lesions justifies histopathological confirmation of all resected specimens, and a low threshold for surgery in nodules with suspicious cytology or high-risk clinical features.