Thyroid Function in Malignant Lymphoma

Thyroid function was studied in 36 patients with various stages of malignant lymphoma. Stage IVB patients exhibited characteristic changes in thyroid biochemistry in the form of lowered triiodothyronine (T3) and elevated free thyroxine (FT4), but normal thyroxine. Moreover, the concentration of thyroxine-binding prealbumin and albumin was lowered, whereas thyroxine-binding globulin was normal. Thyroid-stimulating hormone was slightly elevated but showed a normal increase after administration of thyrotrophin-releasing hormone. Patients with less extensive disease differed only slightly from the controls. The results agree with previous studies of patients suffering from other chronic diseases. The mechanisms underlying the hormonal changes have been only partially elucidated. When investigating patients with disseminated malignant disease for thyroid disease, the above mentioned changes in thyroid biochemistry must be borne in mind. Single analyses of FT4 and T3 may give rise to a false assumption of hyper- or hypothyroid states in patients who are in fact euthyroid.