Rare Columnar Cell Variant Papillary Thyroid Carcinoma with Metastasis to Pancreas and Lungs at Initial Presentation: A Case Report and Review of Literature

Abstract Papillary thyroid cancer (PTC) is the most common endocrine malignancy, accounting for 85% of differentiated cancers. A small percentage PTC variants are considered more aggressive, such as tall cell variant associated with V600E mutation in BRAF gene and rarer columnar variant, which described only 0.2% cases has a poor prognosis. Although locoregional metastases to neck lymph nodes common, distant rare at presentation 5 7% reported literature. We present very case synchronous metastasis lungs indolent focus pancreas initial diagnosis, never been Our patient presented non-radioactive iodine (RAI) responsive diffuse one focal metastatic lesion pancreas. After multidisciplinary discussions, pancreatectomy/metastasectomy was deferred due disseminated multiple lungs, lack pancreas-related symptoms patient, inherent complication risks. The treated systemic therapy using tyrosine kinase inhibitor (lenvatinib), standard care non-RAI showed complete radiologic resolution pancreatic lesion, however, partial yet nonprogressive disease lungs.