SAT566 A Rare Case Of Aggressive Anaplastic Thyroid Presenting As Thyrotoxicosis
Authors: Al-Juboori Amenah , Al-Yousif Yahya , Fomin Svetlana , Sundaram Magesh 
Published: October 2023

Disclosure: A. Al-Juboori: None. Y. Al-Yousif: None. S. Fomin: None. M. Sundaram: None.

Background:Anaplastic Thyroid cancer is a rare neoplasm with a poor prognosis and high mortality rate. Usually, it presents with symptoms like dysphagia and hoarseness. However, it is rarely presented with thyrotoxicosis from the rapid destruction of thyroid follicle cells, causing excessive leakage of preformed thyroid hormones into the circulation. Clinical presentation can vary from a subclinical state to a life-threatening thyroid storm. Management requires an inter-professional team approach.

Clinical Case:77-year-old female patient, who visited the urgent care on August 12 complaining of sore throat, Amoxicillin was prescribed. Presented to ER 10 days later complaining of a headache, gum discomfort, shortness of breath, worsening sore throat, neck pain, and gradual worsening dysphagia to liquids and solids. Physical exam revealed anterior painful and firm neck mass upon palpation. Stridor was noted upon auscultation and was found to be in arterial fibrillation with a rapid ventricular rate for which Amiodarone drip and heparin drip were initiated. IV hydrocortisone 50 mg TID was added to the treatment right away for symptomatic relief. The results of the thyroid function test revealed an increased serum FT4 and FT3, and low serum TSH. Antibodies were normal. Clinical presentation increases the suspicion of undifferentiated thyroid cancer versus lymphoma. CT revealed leftward tracheal deviation along with a big undetermined right thyroid mass with accompanying cervical and supraclavicular adenopathy. IR was consulted urgently for a thyroid biopsy. High-grade anaplastic cancer was discovered after a biopsy with metastasis to the surrounding lymph. The decision was made to transfer the patient to a tertiary care facility for invasive interventions. Anaplastic thyroid cancer accounts for 2-3% of all thyroid gland neoplasm, it often affects persons over the age of 60, and the mean age at the time of diagnosis is 65 years, most common in female population compared to males with a ratio of 2:1. There have been only around 9 other cases reported in the literature in which thyrotoxicosis is the initial presentation of anaplastic thyroid cancer. Diagnosis is usually made via core needle biopsy. 70% of individuals with anaplastic thyroid carcinoma will have contiguous spread and distant metastasis at the time of diagnosis. It most commonly compresses the trachea and esophagus. Given the rapid progression of illness, patients can die from local airway obstruction. Average survival is just 6 months with only 1 in 5 people surviving after 12 months.

Conclusion:Anaplastic thyroid cancer-induced thyrotoxicosis is an uncommon and rare presentation of thyroid neoplasm. Debulking surgery is the cornerstone for removing tumors and securing the patient’s airway along with controlling thyrotoxicosis. A low survival rate was reported in these patients.

Presentation: Saturday, June 17, 2023