Introduction
Anaplastic thyroid cancer (ATC) is a rare cancer that is found in about
1% of thyroid malignant tumors and has an extremely poor prognosis.
Generally, papillary thyroid carcinoma (PTC) grows slowly, but when it
exhibits a rapid growth, it is necessary to bear in mind the anaplastic
transformation. It is known that most of anaplastic transformation
occurs in primary lesions, but rarely occurs in cervical lymph node
lesions or distant metastasis lesions.
We have experienced cases in which metastatic cervical lymph nodes have
undergone anaplastic transformation. In this manuscript, we report our
experience with courses and outcomes of a patient demonstrating
papillary carcinoma in primary lesion but showing anaplastic
transformation in the metastatic cervical lymph nodes with rapid
recurrence after surgery.