Quantitative reverse transcription polymerase chain reaction-based detection of thyroid-specific gene expression in fine-needle aspirate for thyroid cancer recurrence evaluation: a case report and review of the literature.

Abstract

Despite improved surveillance for patients after total thyroidectomy for cancer, there has yet to be a diagnostic method that detects recurrence with 100% accuracy. A 60-year-old woman with a family history of papillary thyroid cancer (PTC) underwent total thyroidectomy and radioactive iodine ablation. On postoperative surveillance, ultrasound examination of the neck demonstrated a focus concerning for recurrence and a fine-needle aspirate (FNA) was performed. The cytology report was nondiagnostic and, hence, RNA was extracted from the specimen followed by reverse transcription (cDNA), and quantitative real-time polymerase chain reaction (qRT-PCR) to detect thyroid-specific gene expression (thyroglobulin =Tg; sodium-iodide symporter = NIS; thyroperoxidase = TPO). Expression of select thyroid-specific genes was demonstrated, and given the patient's remarkable cancer and family history, surgical resection was elected. Final pathology demonstrated follicular adenoma. This case demonstrates a novel approach used in the evaluation for recurrent thyroid cancer as an adjunct to FNA cytology.