[An autopsy case of anaplastic thyroid carcinoma that transformed from papillary carcinoma within 5 years from...

An 84-year-old man was admitted to our hospital with right shoulder pain. He had been suffering from well-differentiated papillary thyroid carcinoma since 1994, and had undergone surgery three times, including procedures due to recurrence. Since CT showed a right cervical tumor, recurrence of thyroid carcinoma was diagnosed. He died in September 1999 due to progressive respiratory failure. Autopsy was performed and pathological examination revealed the recurrent tumor and metastatic lesions had totally transformed to anaplastic thyroid carcinoma. Since anaplastic carcinoma is characterized by exceptionally rapid progression with dire prognosis, physicians should be aware of the major risk factors of anaplastic transformation in elderly males aged over 60 years old, with repeated relapses of differentiated carcinoma, and a history of tumor irradiation.