Friday, April 27, 2007

Kidney Cancer Presenting as a Thyroid Nodule

50 Y/O female was referred to me to evaluate a thyroid mass seen on MR to evaluate a
lateral neck mass. The mass was painless. She did not have a prior history of thyroid disease. The thyroid was nodular on the right. The neck mass on the right was 2 cm and not tender. The ultrasound confirmed a mass in the thyroid on the right, and smaller masses on the left. Masses were also noted in the area of both inferior parathyroid glands. The blood flow by power Doppler was a firestorm pattern on the right side only. She was normal by TSH,T4, and TPO antibodies. Prior FNA of the lateral neck mass was non-diagnostic. Prior studies revealed a high serum calcium. I confirmed that, but the PTH was ND. The parathyroid area masses had to be abnormal nodes. This was not hyperparathyroidism. When the calcitonin was also ND, I knew we were not dealing with a MEA syndrome, Medullary thyroid cancer, parathyroid adenoma. I decided to biopsy the neck mass,and do flow cytometry,and thyroglobulin washings to rule out lymphoma, and metastatic thyroid cancer. Both were negative. The cells seen in the neck and thyroid nodule by US guided FNA were very large and consistent with a bad cancer of unknown etiology. When she returned to discuss results, she told me she had a bump on the top of her head in the scalp, that came on the same time the neck mass was noted. It was red, and pulsated 1.5 cm in size. She was told it was nothing to worry about. I ordered a PET/CT because there was still unanswered questions on the origin of these cells. Was it anaplastic thyroid cancer, or metastatic cancer to the thyroid from somewhere else. Both of these possibilities are very rare clinical practice. Usually, thyroid mets from somewhere such as breast are incidental findings at autopsy, not presenting as a thyroid nodule. The PET/CT was abnormal. A >9 cm mass was seen in the kidney. Masses were seen in the liver, lungs, pancreas, neck lymph nodes, celiac plexis, and infiltration into the thyroid gland on both sides. The bump on the top of her hear was positive as well.

In 30+ years I have never had a case like this. Metastatic Anaplastic Ca to the thyroid from possible kidney origin. A excision biopsy of the neck mass to try to determine the origin, and a referral to an oncologist was planned.