SUN-491 A Diagnosis of Thyroid Cancer Reveals a Triple Threat

Abstract

Introduction: The risk of secondary malignancies is increased in patients with papillary thyroid cancer (PTC). It is not completely clear if this risk is due to radioactive iodine treatment or due to other causes. We present a case of a patient diagnosed with papillary thyroid cancer (PTC) found to have lung cancer and small lymphocytic lymphoma which appear to be unrelated to radioactive iodine treatment.Case Presentation: A 72 yo woman with a history of Graves’ disease, atrial fibrillation, and hyperparathyroidism initially presented to care for weight loss. She was found to have hyperthyroidism and was treated with methimazole. Thyroid ultrasound revealed multiple nodules including a 17mm right lower pole nodule with irregular borders for which she underwent FNA. Pathology demonstrated atypical-cells of undetermined significance (AUS), but thyroseq revealed a BRAF V600E mutation. She underwent total thyroidectomy with pathology showing multifocal thyroid cancer, 12mm and 0.8mm with 3/11 involved lymph nodes and right parathyroid adenoma. Given a questionable lower left lung nodule on preop CXR, she underwent CT chest which revealed a 2cm lung nodule. She had video assisted thoracoscopic (VATS) left lower lobe wedge resection with completion left lower lobectomy for a 3 cm lung adenocarcinoma with negative margins and 33 negative lymph nodes. She was subsequently treated with RAI after recovery from VATS procedure. Pretreatment thyroglobulin was 0.8 ng/ml with negative thyroglobulin antibodies. One month after her RAI treatment, ultrasound of the neck revealed suspicious bilateral level IV lymph nodes which increased in size during short term follow up. Serum thyroglobulin was 0.3ng/ml with negative antibodies and TSH 0.29 mIU/L. Biopsy of right level IV lymph node was positive for PTC with thyroglobulin washout >5000 while left level IV lymph node was negative for PTC and Tg washout was 0.1. She subsequently underwent right-sided modified radical neck dissection, with lymph nodes revealing PTC also involved by small lymphocytic lymphoma. She had repeat RAI ablation for thyroid cancer and is being actively monitored for her small lymphocytic lymphoma and lung adenocarcinoma.Conclusion: We present a patient with no known history of malignancy who presented with 3 de novo primary malignancies. This case may demonstrate an increased risk of malignancy in patients with thyroid cancer not necessarily related to radioactive iodine treatment.