Incidental thyroid carcinoma in benign thyroid disease: a longitudinal descriptive study

Abstract

BACKGROUND: An incidental thyroid carcinoma (ITC) is a thyroid malignancy that is not clinically or cytologically detected preoperatively. The incidence of ITC is between 10% - 20% in the literature. OBJECTIVES: The study was undertaken to assess the incidence of ITC in patients presenting with benign disease of the thyroid to University Surgical Unit, Colombo North Teaching Hospital, Sri Lanka. METHODS: A longitudinal descriptive study was conducted spanning from November, 2002 to October, 2015 on a cohort of all patients who underwent total thyroidectomy with cytologically benign thyroid disease. FNAC was performed on all palpable lesions to detect presence of malignancy. Presence of autoimmune thyroiditis was taken as an exclusion criterion due to its known association with malignancy of the thyroid. Post-thyroidectomy histopathological diagnoses were provided by Department of Pathology, University of Kelaniya, Sri Lanka and were collected prospectively. Statistical analysis was done by Fisher’s exact test using SPSS software, version 20. RESULTS: Hundred and sixty seven patients (n=167) underwent total thyroidectomy (Male – 2, Female – 17, Median age = 40.25 years, Range 28 – 62 years). ITC was found in 11.38% (19/167) with a female preponderance (13/19). A majority (89.4%) were euthyroid. CONCLUSIONS: Incidence of ITC in benign thyroid disease is 11.38% which may have implications for the management in benign thyroid disease.