Hyperfunctioning papillary thyroid carcinoma - a case report and literature review.

Background: Malignant hyperfunctioning thyroid nodules are rare and more likely to occur in follicular cancer types rather than papillary variants. The authors present a case of a papillary thyroid carcinoma associated with a hyperfunctioning nodule.

Methods: A single adult patient submitted to total thyroidectomy with the presence of thyroid carcinoma within hyperfunctioning nodules was selected. Additionally, brief literature was conducted.

Results: An asymptomatic 58-year-old male was subjected to routine blood analysis and a TSH level of <0.003 mIU/L was found. Ultrasonography revealed a 21 mm solid, hypoechoic, and heterogenous nodule with microcalcifications in the right lobe. A fine needle aspiration guided by ultrasound resulted in a follicular lesion of undetermined significance. A ^99mTc thyroid scintigram was followed and identified a right-sided hyperfunctioning nodule. Another cytology was performed and a papillary thyroid carcinoma was derived as a result. The patient underwent a total thyroidectomy. Postoperative histology confirmed the diagnosis and a tumor-free margin with no vascular or capsular invasions.

Conclusion: Hyperfunctioning malignant nodules are a rare association, although a careful approach should be led since major clinical implications arise. Selective fine needle aspiration in all suspicious ≥1 cm nodules should be considered.