Screening ultrasonography for thyroid pathology among medical students in western Nepal; a cross-sectional study

Abstract

Background: Thyroid disorders are highly prevalent globally, yet subclinical disease remains undercharacterised in young South Asian adults. Medical students constitute a unique cohort for population-level screening given their demographic diversity and healthy baseline.

Aim: To determine the prevalence and sonographic spectrum of thyroid pathology among undergraduate medical students and to correlate findings with sex, anthropometry, and biochemical parameters.

Methods: A prospective cross-sectional study was conducted among 361 medical students (219 male, 142 female; mean age 22.8 ± 2.2 years) following Institutional Review Committee approval. High-frequency (7.5–12 MHz) B-mode Doppler ultrasonography was performed by a single experienced radiologist. Nodules were classified using the 2017 ACR TI-RADS lexicon. Biochemical evaluation (TSH, free T4, anti-TPO antibodies) was performed in participants with sonographic diagnoses. Data were analysed using SPSS v26.0 (IBM Corp., USA); p<0.05 was considered significant.

Results: Thyroid abnormalities were detected in 147 participants (40.7%). Chronic autoimmune thyroiditis (CAT) was identified in 30 students (8.3%; F:M ratio 1.1:1); subclinical hypothyroidism was present in 14 CAT-positive participants (46.7%) and anti-TPO antibodies were elevated in 7 (23.3%). Thyroid nodules were present in 113 students (31.3%), predominantly colloid/colloid cysts (81/113; 71.7%). ACR TI-RADS TR 5 fine-needle aspiration cytology confirmed Bethesda Category VI papillary thyroid carcinoma in one asymptomatic participant. Mean total thyroid volume was significantly higher in males than females (8.73 ± 2.03 vs. 6.17 ± 1.94 cm³; p<0.001). Cervical lymphadenopathy of benign character was observed in 103 participants (28.5%).

Conclusion: Screening ultrasonography reveals a substantial burden of subclinical thyroid pathology among asymptomatic medical students, including one case of papillary thyroid carcinoma. Combined sonographic and biochemical screening is recommended in young adults in Nepal given the ongoing iodine nutritional transition.