SUN-608 A Rare Miliary Tuberculosis-Like Presentation of Papillary Thyroid Cancer: A Case Report with Literature Review

Abstract

Papillary thyroid cancer (PTC) is the most common thyroid cancer with a very favorable prognosis [1]. It commonly presents as a palpable thyroid nodule or an incidental finding of thyroid nodule(s) seen on imaging. The most common site of metastases in PTC is lung, however, the incidence is very low. Presence of metastasis can drastically affect the prognosis of PTC [2]. We discuss here a case of an asymptomatic 34-year-old male, who initially presented with positive tuberculin skin test and was found to have diffuse micronodular pulmonary disease on chest imaging. Initially being diagnosed with pulmonary TB, he received 6 months of empiric anti-tuberculous therapy, although, repeated sputum and blood cultures for acid-fast bacilli remained negative. However, patient had no improvement of pulmonary lesions on interval imaging. Another interesting incidental finding, seen on lung CT, was the presence of multinodular appearance of the thyroid gland which prompted further imaging of the neck. CT scan of the neck showed multiple enhancing necrotic masses in the right thyroid gland with similar lesions in cervical lymph nodes. Considering the patient’s preliminary diagnosis of pulmonary TB, these lesions were thought to be secondary to tuberculosis. However, given that different types of thyroid malignancies can have a similar presentation, further workup was initiated. Subsequent FNA was positive for PTC on the right thyroid nodule. A total thyroidectomy with neck dissection was performed and confirmed the presence of a 2 cm PTC with cervical lymph node metastases. Post-operative non-stimulated thyroglobulin was very high at 2858. Thyroglobulin antibody was negative. The post radioactive iodine therapy (RAI) whole body scan (WBS) showed impressive bilateral lung uptake. Widespread pulmonary nodules, similar to that seen in miliary TB, is a rare initial presentation of PTC. However, as our case highlights, the added presence of thyroid nodules should prompt further investigation to rule out PTC as the cause of pulmonary lesions. 1. Aschebrook-Kilfoy, B., et al., Thyroid cancer incidence patterns in the United States by histologic type, 1992-2006. Thyroid, 2011. 21(2): p. 125-34. 2. Lang, B.H., et al., Staging systems for papillary thyroid carcinoma: a review and comparison. Ann Surg, 2007. 245(3): p. 366-78.