Modified Fine-Needle Aspiration Biopsy for Calcitonin, Procalcitonin and Carcinoembryonic Antigen Levels in the Diagnosis of Thyroid Nodules With Medullary Thyroid Carcinoma

Abstract

Background: The diagnostic tests have low sensitivities in detecting medullary thyroid cancer (MTC). We describe a modified fine-needle thyroid nodule biopsy (MFNB) technique that improved the diagnostic accuracy. MFNB was performed in three patients with MTC. Methods and results: A 41-year-old female presented with thyroid nodules and a family history of MTC. Fine-needle biopsy (FNB) of the thyroid nodules showed non-confirmatory cytology. MFNB established cytology more confirmatory of MTC. Additionally, intravenous administration of calcium-stimulated serum concentrations of procalcitonin (PCt) level, in addition to calcitonin (Ct) and MFNB, also confirmed elevated levels of Ct, PCt, and carcinoembryonic antigen (CEA) in the aspirate samples. The diagnosis of MTC was finally confirmed histologically after thyroidectomy. A 54-year-old female presented to our clinic for evaluation of a right thyroid nodule. An MFNB compared to standard FNB showed a more confirmatory MTC cytology along with markedly elevated levels of Ct, PCt, and CEA in the aspirated samples by the MFNB technique. Additionally, intravenous calcium administration increased PCt serum concentrations. The diagnosis of MTC was confirmed after surgery. A 65-year-old female reported to our clinic with a diagnosis of multinodular goiter and a family history of thyroid cancer. FNB showed atypical cells, although MFNB was more confirmatory for diagnosing MTC. Elevated serum PCt levels were also seen with calcium stimulation and MFNB aspirate samples also confirmed elevated levels of Ct, PCt, and CEA. MFNB of nodules in three patients with surgically confirmed benign thyroid confirmed low levels of Ct, PCt and CEA levels in the aspirate samples. Similar findings were confirmed in a patient with papillary thyroid cancer. Conclusion: MFNB was more confirmatory for diagnosing MTC than conventional FNB. Determining Ct, PCt, and CEA levels in MFNB aspirate samples may improve the diagnostic accuracy. J Endocrinol Metab. 2017;7(1):5-17 doi: https://doi.org/10.14740/jem371w