Endocrine Abstracts

We present the case of a 41-year-old man with a history of testicular seminoma treated with surgery and chemotherapy, and post-chemotherapy chronic kidney disease. He was initially referred to Otolaryngology for a 1-month history of neck mass sensation, with associated dysphonia, dysphagia and dyspnea. On examination, thyroid gland was enlarged. Fibroscopy was performed in consultation, revealing paralysis of the left vocal cord. The patient was referred to Endocrinology and Surgery departments. A cervicothoracic CT and ultrasound were requested. The CT showed a thyroid neoformative lesion with decreased tracheal lumen and pathological lymph nodes in levels III, IV, V, and VI bilaterally. The ultrasound showed a TIRADS-5 thyroid nodule in the left lobe, in which fine-needle aspiration (FNA) was performed, being insufficient for diagnosis. FNA was also performed on a pathological lymph node at right level III, with thyroglobulin 4729.62 ng/ml and TTF-1 positive, indicating thyroid origin, but unable to determine whether it was a follicular neoplasm or a follicular variant of papillary neoplasm. Biopsy-assisted guided (BAG) was requested, which could not confirm the diagnosis either. A blood test revealed normal calcitonine (5.23 pg/ml). At the same time, upper gastrointestinal endoscopy (UGE) and bronchoscopy were requested to assess resectability. UGE showed doubtful esophageal infiltration. Bronchoscopy revealed lesions in left tracheal wall, from which biopsies were taken. Histological study revealed positive immunoreactivity for thyroglobulin and TTF-1, confirming thyroid origin, but unable to state whether it was metastasis of thyroid carcinoma or ectopic thyroid tumor. The case was presented to a multidisciplinary committee, and neoadjuvant treatment with Lenvatinib was decided. After 1.5 months, a cervicothoracic CT showed partial response to treatment, so Lenvatinib was continued. After another 1.5 months, a new CT showed no significant changes and a new bronchoscopy continued visualizing neoplastic-appearing tracheal lesions, with a biopsy compatible with papillary neoplasia. Likewise, a new thyroid BAG was performed, also compatible with papillary carcinoma. With all this, surgical treatment was decided, being necessary total thyroidectomy, bilateral central and lateral lymph node dissection, resection of second to fourth tracheal rings with reconstruction, and temporary tracheostomy. This case aims to highlight the importance of individualized management of invasive differentiated thyroid cancer despite the difficulty in reaching an accurate diagnosis. Invasion of surrounding structures can lead to aggressive procedures such as tracheal resection, so there is a potential role for neoadjuvant therapy with tyrosine-kinase inhibitors in these patients, although it does not always avoid these procedures.