Prevalence of thyroid cancer at a medical screening center: pathological features of screen-detected thyroid carcinomas.
OBJECTIVE
To assess the incidence of thyroid malignancy in an adult population screened by high-resolution ultrasonography at a medical screening center and to compare the clinical and pathological features of screen-detected thyroid carcinomas to symptomatic overt thyroid carcinomas.


METHODS
We calculated the prevalence of screen-detected thyroid cancer at a medical screening center using high- resolution ultrasonography and fine needle aspiration. We then compared the clinical and pathological features of screen-detected thyroid cancers (n = 46) to clinical symptomatic thyroid cancers (n = 157). We evaluated age, gender, size, perithyroidal extension, lymphovascular extension, stage, histological lymph node metastasis, and the type of cancer. We also compared the above findings of micropapillary carcinomas to papillary thyroid carcinomas that were larger than 1cm in diameter.


RESULTS
Screen-detected thyroid nodule patients were 2,747 (37%) of 7,491 patients. Nodules selected for fine needle aspiration were 658 and cytology confirmed malignancy were 79 (12%) nodules. When screen-detected thyroid cancers (n = 46) were compared to symptomatic overt thyroid cancers (n = 157), only statistically significant factor was size (p = 0.002). Papillary thyroid carcinomas that were larger than 1 cm had more frequent capsular invasion (p = 0.000) and a higher stage (p = 0.027), and a higher prevalence of lymph node metastases (p = 0.002).


CONCLUSIONS
Screen-detected thyroid cancers should be managed as same as symptomatic thyroid cancers in respect to size, and an assessment should strictly be based on the ultrasound features and fine needle aspiration biopsy findings.
Choi
Yoon Jung
YJ
Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea. yoonchoi99@yahoo.com
Park
Yong Lai
YL
Koh
Jang Hyun
JH
D000328:Adult; D000367:Age Factors; D044963:Biopsy, Fine-Needle; D002291:Carcinoma, Papillary / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000473:pathology; D005260:Female; D006801:Humans; D007723:Korea / Q000453:epidemiology; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D015995:Prevalence; D012737:Sex Factors; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000473:pathology; D014463:Ultrasonography