U024

Detecting thyroid malignancy in hyperfunctioning nodules

L. Yang, F. Palazzo, R. Lingam, S. McHardy-Young

Jeffrey Kelson Centre for Diabetes & Endocrinology, Central Middlesex Hospital

Introduction

Thyroid nodules are common in clinical practice; “hot” or autonomously functioning nodules are considered almost universally benign. Current guidelines recommend no further imaging or cytological evaluation for hyperfunctioning nodules detected by scintigraphy. We present two recent cases of papillary thyroid carcinoma diagnosed in thyrotoxic patients both presenting with palpable thyroid nodules and a strong family history of hyperthyroidism.

Case 1

A 29 year old Pakistani male presented with weight loss and lethargy. A firm right thyroid nodule was palpable. Initial TFTs: TSH < 0.01 mIU/L (0.35-4.94), fT4 20.4 pmol/L (9.0 – 19.0), fT3 7.5 pmol/L (2.6 – 5.7). TPO & TSH receptor antibodies positive. Scintigraphy demonstrated a solitary hot nodule in the right lobe. Thyroid MDT concluded that the likely diagnosis was Hashitoxicosis. Medical treatment failed to normalise levels; the patient subsequently underwent radioiodine treatment. At one year post radio-iodine a residual right thyroid nodule was still present, so follow-up US neck was performed. This showed a 3cm hypoechoic right thyroid lobe with an enlarged level 4 right cervical chain lymph node. FNA showed features consistent with papillary thyroid carcinoma (Thy5). The patient underwent a total thyroidectomy and neck dissection. Histopathology confirmed classical papillary thyroid carcinoma with 11/36 positive lymph nodes dissected.

Case 2

A 33 year old Filipino female was referred with symptoms of anxiety and tiredness. Examination revealed an asymmetrical, mildly nodular goitre. Initial TFTs: TSH 0.34 mIU/L (0.35 – 4.94), fT3 15.5 pmol/L (2.6 – 5.7). US neck showed a 2.6 x 3.3cm heterogeneous nodule in the right superior thyroid exhibiting increased vascularity with prominent right sided cervical lymph nodes. FNA was strongly suggestive of papillary thyroid carcinoma (Thy5) and the patient underwent total thyroidectomy with right modified radical neck dissection.

Discussion 

Current guidelines usually exclude US imaging in hyperthyroidism. However the incidence of malignancy in hyperfunctioning nodules is variably quoted to range from 3.1% to 18%, and there are no specific clinical features to reliably distinguish between malignant and benign disease. These two cases illustrate the importance of MDT discussion, and utility of US scanning for palpable “hot” nodules.