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 BRAF^V600E and I582 M mutations along with upregulation of tumor markers in metastatic tissue. The presence of BRAF^V600E 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.