Hurthle Cell Carcinoma Of The Thyroid And The Issue Of Adjuvant External Beam Radiation Versus Ablative Radioiodine

We report a case of a 46-year-old Malay man with a background history of hypertension and type 2 diabetes mellitus, who presented with an enlarging thyroid nodule. He first noticed the nodule back in 2003 and began to develop hoarseness of voice in the past 2 years. During that period, he was investigated by a secondary institution until a week prior to admission when he started to complain of shortness of breath. Physical examination revealed a stout gentleman with an enlarged thyroid mass measuring 10 cm x 14 cm with multiple cervical lymphadenopathies. He was in respiratory distress with marked inspiratory stridor on a semi-recumbent position. His tidal flow-volume curve revealed features of external compression with marked flattening of the inspiratory limb typically seen in airway obstruction due to an external compression. A computerized tomogram showed a large heterogeneously enhancing right thyroid gland mass, which measured 7.6 cm x 6.1 cm x 9.0 cm with the narrowed (0.5 cm diameter) trachea pushed to the right side. There were tumour erosions into the adjacent left thyroid and cricoid cartilages with multiple enlarged cervical and mediastinal lymphadenopathy. Numerous nodules which represented pulmonary metastases were also present in both lung fields. He was immediately brought to the operating theater where he underwent an urgent total thyroidectomy. As a result of the extensive nature of the disease, a major portion of the infiltrated tumour into the tracheal ring and esophagus was not excised. The histopathological examination revealed follicular thyroid carcinoma of the oncocytic variant also known as hurtle cell carcinoma, with lymph node metastases. Immediately after surgery he was subjected to a course of external beam radiation to the thyroid bed, expedited by his persistent problem of dyspnoea. He was planned for ablative radioiodine treatment due to the concern for the pulmonary metastases, a course of action which was uncharacteristically out of line with standard guideline. The management of Hurtle cell carcinoma, histologically classified under follicular thyroid cancers, has always raised a certain amount of contention between surgeons, oncologists and endocrinologists alike. On the other hand, labeled as poorly differentiated thyroid cancers due to its low radioiodine avidity (10% in conservative literature), most preferred external beam radiation to ablative radioiodine as the adjunct therapy after surgery for Hurtle cell carcinoma. However, those who advocated radioiodine believed that due to its poor prognosis as a result of the tendency for widespread metastases, the remote chance that it might take up radioiodine should not be dismissed readily. Department of Medicine, UKM Medical Centre, Kuala Lumpur