MON-442 Tall Cell Variant of Papillary Thyroid Carcinoma Presenting Acutely as a Right Thyroid Mass and Thyroiditis - an Unusual Presentation

Abstract

INTRODUCTIONAggressive malignant thyroid tumors (AMTT) can rarely present with signs and symptoms mimicking that of acute suppurative thyroiditis (AST). In its early course, correct diagnosis may be difficult but a prompt recognition is crucial. We report an interesting case of an aggressive papillary thyroid cancer with presenting acute symptoms masquerading as AST.CLINICAL CASEA 50-year-old Caucasian male was admitted for 2 day history of sore throat, odynophagia, low grade fever with a tender and enlarging right neck swelling, not improving with oral antibiotics. CT neck showed a 5.8 x 4.5cm mass in right thyroid lobe with shallow retropharyngeal effusion. Labs showed elevated WBC 10.7 x 109/L (4–10.5), ESR 20 mm/hr (0–12), CRP 92.93 mg/L (0.2–10), with negative rapid strep and IgM for viruses EBV and CMV. Thyroid function tests were normal. Ultrasound neck showed an ill-defined 6.5 cm hypoechoic mass with cystic component and increased vascularity and calcification, replacing the right thyroid lobe. Due to concern for thyroid abscess he underwent urgent aspiration. Fluid analysis and cultures were negative for bacterial source. FNA (fine needle aspiration) of one specimen was suspicious for follicular neoplasm with predominant hurtle cells and suspicious for thyroid neoplasm with papillary architecture in the other. Core biopsy was suspicious for papillary carcinoma but limited due to scant amount of tissue. Affirma unavailable due to insufficient RNA yield. Flow cytometry was negative for abnormal lymphocyte population. Repeat CT neck 3 weeks later was concerning for metastatic lymphadenopathy. He underwent total thyroidectomy with lymph node (LN) dissection and pathology showed papillary thyroid cancer, tall cell variant, tumor size 6 cm, predominantly hemorrhagic, extending to perithyroidal strap muscles and involving 5/6 LN in right trachea-esophageal groove. It was a stage I, pT3bN1aMx cancer. Subsequently, he underwent thyrogen stimulated I-131 ablation of residual thyroid carcinoma with pretherapy scan showing increased uptake in thyroid bed and a satellite lesion suspicious for LN metastasis. Post-ablative scan showed no other new lesions. He is now on levothyroxine suppressive therapy.CONCLUSIONEarly course of AMTT can rarely present as AST, both being progressive and fatal diseases. Our case had a typical presentation of AST, causing delay in diagnosis of his very aggressive form of thyroid cancer. Gross pathology showed predominantly hemorrhagic areas in the tumor with central necrosis, which was likely the cause of acute mass with systemic signs suspicious for infection. One should consider an alternative diagnosis in suspected cases of AST in the absence of positive cultures or lack of improvement with parenteral antibiotics. It is imperative to make a diagnosis without any delay as prognosis for either condition depends on prompt recognition and treatment.