Combination of medullary thyroid cancer and renal cell carcinoma in one patient

Patients who received treatment for the first malignant neoplasm remain in the group at increased risk of developing a second primary tumor throughout their later life. A rare case of medullary thyroid cancer and renal cell carcinoma of the kidney is described in one patient. Medullary thyroid cancer is an orphan disease. The patient and his first-line relatives underwent molecular-genetic testing, the presence of a hereditary form of medullary cancer was excluded. During the observation, malignant kidney formation was detected, and surgical treatment was performed. The patient because of treatment and surveillance does not have data for the progression of thyroid cancer and kidney cancer, compensation for concomitant diseases has been achieved. When observing patients with medullary thyroid cancer, it is necessary to use the existing modern diagnostic arsenal, including positron emission tomography, since patients remain in the group at increased risk of disease progression and development of the second tumor throughout the entire subsequent life. In addition, this case clearly illustrates the need for a routine study of calcitonin as a diagnostic marker for the progression of medullary thyroid cancer.