Clinical presentation: A 39-year-old was referred for FNA of the thyroid because of a newly developed nodule. She had been operated with colon cancer with hepatic metastasis a year before the thyroid examination.

Palpation: a firm nodule in the right lobe.

Functional state: euthyroidism. 

Ultrasonography. The thyroid was intact except for a hypoechogenic inhomogeneous nodule in the right thyroid. 

Cytology resulted in papillary cancer.

Histopathology: metastasis of a colon cancer to the thyroid.

The postoperative evaluation of the patient revealed metastasis to the lung and to the liver.

Comments.

1. I personally made two mistakes.

   •  The obvious one was that I did not reveal that the patient had a colon cancer. On evaluation, she did not mention the previous oncological disease and I did not assume that the healthy-looking patient would have had a tumor before. At the time of the investigation, in 1995, there were no electronic database of patients in Hungary available. Either way, I wasn't thorough enough.

   •  The less obvious failure was my cytological diagnosis. Knowing the final diagnosis, of course, I would say otherwise. And re-examining the cytology sample later helped to avoid a similar mistake. Although the cytological picture resembles that seen in papillary cancer, the cytological pattern should raise colonic cancer. The clue is the palisading arrangement of tumor cells.

2. There was another failure which affected our evaluation team. The surgeon was overconfident in my cytological diagnosis. Having learned the lesson of this case, we later agreed to discuss openly if there is any doubt as to the correctness of the cytological diagnosis.