ENT case 3. Thyroid mass.

•Diagnosis: high grade follicular cell-derived non-anaplastic thyroid carcinoma, aka: poorly differentiated thyroid carcinoma

•In the current WHO book, poorly differentiated thyroid carcinoma is classified in the same category with high grade papillary thyroid carcinoma, high grade follicular thyroid carcinoma, and high grade oncocytic follicular carcinoma.

•Features of this category of tumor include increased mitotic count and/or tumor necrosis

•Caution: increased mitotic count does not portent worse behavior for pediatric thyroid tumors.