A Case of Rapidly Growing Poorly Differentiated Thyroid Carcinoma

A 64-year-old man seen elsewhere for recurrent bloody sputum was found in computed tomography (CT) to have a 2 cm thyroid tumor invading the trachea but no recurrent nerve palsy. Fine-needle aspiration biopsy showed papillary carcinoma of the thyroid gland. He was scheduled for total thyroidectomy and tracheal reconstruction. On admission, he reported dyspnea on exercise. The tumor grew rapidly invading the cricoid cartilage. Suspected anaplastic carcinoma was not seen. Total thyroidectomy and laryngectomy yielded a pathological diagnosis of poorly differentiated carcinoma as defined in General Rules for the Designation of Thyroid Cancer by the Japanese Society of Thyroid Surgery. Poorly differentiated carcinoma of the thyroid is a new pathological concept that we report with a review of the literature.