Circulating epithelial cell enumeration facilitates the identification and follow-up of a patient with early stage papillary thyroid microcarcinoma: A case report

•An individual with no sign of cancer had persistently high CEC counts.•Follow-up medical examinations revealed that the patient had early stage PTMC.•The CEC counts were correlated with serum Tg and the patient's disease status.•CEC testing facilitates the identification and management of patients with PTMC.

BackgroundThis study examines whether the measurement of circulating epithelial cells (CECs) facilitates the identification and follow-up of a patient with thyroid cancer.MethodsA 29-y-old woman with no cancer history was enrolled as a healthy control in a CEC study. CECs were enriched from the peripheral blood by the negative selection system PowerMag. Various medical examinations were performed on the patient to establish the diagnosis and to follow-up her disease status during treatment.ResultsThis patient had unexpectedly high CEC counts that were sustained for more than two weeks. Thyroid gland ultra-sonography revealed lesions in the left lobe that could not be confirmed as cancer by magnetic resonance imaging, 18F–fludeoxyglucose-positron emission tomography–computed tomography or cytopathological analysis, but were histologically confirmed after thyroidectomy as papillary thyroid microcarcinoma. Both the CEC count and serum thyroglobulin (Tg) concentration were significantly decreased after thyroidectomy, and they and the patient's disease status were correlated during remnant ablation therapy. The CEC count returned to normal when the patient was disease-free 10 months after thyroidectomy.ConclusionsCEC testing facilitates the identification of individuals at risk for cancer. Longitudinal follow-up of the CEC count may complement serum Tg testing for monitoring the status of patients with thyroid cancer.