Sonographic correlation of thyroid nodules with ultrasound aided fine needle non aspiration cytology

Abstract

Objectives: To describe the sonographic patterns of thyroid nodules in patients undergoing thyroid ultrasound, to correlate sonographic characteristics of thyroid nodules to ultrasound aided fine needle non aspiration(US-FNNA) cytology and to determine the sensitivity and specificity of Ultrasound in characterising thyroid nodules.
Design: Cross sectional study.
Setting: The department of Radiology at Mulago Teaching and National Referral Hospital in Kampala Uganda. The Hospital is a 1,500-bed unit providing tertiary diagnostic, curative, rehabilitative, preventive and teaching services. Patients were recruited from both Medical and Surgical outpatient thyroid clinics.
Subjects: All patients with thyroid nodules > 5 mm and who consented to have US aided-FNNA were enrolled consecutively.
Results: One hundred and eighty one (181) participants were enrolled and final diagnoses were concluded in 177 of the participants (analysed) while four participants were excluded due to inadequate samples. The participants' age range was 19 to 83 years (mean age - 42 years ) and 93% were females. Five percent (n=9) were malignant, 18% suspiscious (n=34) and benign (n=134). The sonographic characteristics that were significantly correlated with final cytology diagnosis were a taller than wide AP diameter, micro-calcifications, heterogeneous and hypoechoic echo-patterns. Heterogeneous, hypoechoic and central vascularity had the highest sensitivity while wider than tall, anteroposterior diameter, no lymphadenopathy, and macro/no calcifications had the highest specificity.
Conclusion: Sonographic features of micro-calcifications, taller than wide AP diameter, central vascularity and hypoechogenicity warrant US-FNNA. A bigger study correlating thyroid sonography with histological diagnosis is recommended.