Evolution of Papillary Thyroid Carcinoma into Tall Cell Variant and TENIS Syndrome

We herein report an unusual case of a 55-y-old woman with papillary carcinoma of the thyroid, who presented with multiple recurrences, with its subsequent evolution to tall cell variant and thyroglobulin-elevated negative iodine scintigraphy (TENIS) syndrome. During the course of the disease the lesions became non-iodine-concentrating with an increased proportion of tall cells and evidence of local and distant metastasis. Molecular analysis of the tissue specimen demonstrated BRAFV600E and I582 M mutations along with upregulation of tumor markers in metastatic tissue. The presence of BRAFV600E mutation and other markers warrants further investigation in future studies to define their precise implications for determining the aggressiveness and development into tall cell variant and TENIS.