The existence of small cell thyroid tumors with EWSR1-FLI1 rearrangement together with neuroendocrine and/or carcinomatous differentiation raises not only differential diagnostic problems but also a very interesting therapeutic dilemma.    ///    The existence of small cell thyroid tumors with EWSR1-FLI1 rearrangement together with neuroendocrine and/or carcinomatous differentiation raises not only differential diagnostic problems but also a very interesting therapeutic dilemma. 