Effect of chemotherapy on thyroid hormone concentration in patients with malignant hematologic diseases.

Malignant hematologic diseases are severe illnesses for which complex forms of treatment are used and to which a great variety of metabolic changes are anticipated. Both lymphomas and leukemias, as well as chemotherapy, can induce abnormalities in thyroid hormone metabolism without overt disease, thus leading to what is known as euthyroid sick syndrome (ESS). In the present report, 25 patients with lymphomas and leukemias were studied to evaluate the effect of chemotherapy on thyroid hormone concentration. After chemotherapy, the most frequent and significant alteration was a decrease in serum triiodothyronine concentration.