Concurrent Anaplastic and Papillary Thyroid Carcinoma Manifesting as a Thyrocutaneous Fistula

Anaplastic thyroid carcinoma (ATC) is a highly aggressive form of thyroid cancer with poor prognosis. Differentiated thyroid carcinoma (DTC) including papillary thyroid carcinoma (PTC) is more common and known to have a favorable outcome after treatment. Here, we report a case of a 59-year-old lady with a long-standing goiter presenting with a discharging anterior neck mass. Fine-needle aspiration cytology (FTAC) of the mass resulted with malignant cells. She underwent surgery, and histopathological examination revealed both ATC and PTC features. Mutation analysis was also performed, and results were positive for BRAF 600VE mutation. She received radiotherapy and also chemotherapy post-surgery. Treatment was well tolerated. The relatively favorable survival of this patient may suggest that synchronous ATC and DTC may have better prognosis than ATC alone. The objective of this article is to report the unique clinical presentation and favorable prognosis with combined treatment modalities.