A Case of Occult Anaplastic Thyroid Cancer Presenting as Huge Renal Mass

Abstract

Anaplastic thyroid cancers (ATC) are a rapid growing and highly lethal form of thyroid cancer. Distant metastases of ATC are detected in about half of patients. Clinically, it is very rare to metastasize to the kidney. The most common initial symptoms of ATC are a palpable neck mass and accompanying compression symptoms of the upper aerodigestive tract. A 68-year-old patient was referred with a huge renal mass, which was detected during the evaluation of abdominal pain. Left total nephrectomy was performed. Histologically, the kidney tumor was a metastatic anaplastic thyroid carcinoma. To our knowledge, it is the first case of occult ATC presenting as a huge renal mass.