title: Hyponatraemia and hypothyroidism in a previously irradiated case of carcinoma of the tongue.
abstract: A case of squamous cell carcinoma of the tongue was complicated by post operative hyponatraemia. The criteria for the syndrome of inappropriate secretion of anti diuretic hormone, [ADH] (SIADH) were met but the patient remained hyponatraemic despite adequate treatment. The patient had previously received radical external radiotherapy to the neck and was found to be profoundly hypothyroid. Correction of the hypothyroid state led to clinical and biochemical recovery. The frequency of post-irradiation hypothyroidism and the possible mechanisms of hypothyroid-induced hyponatraemia are discussed.
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000150:complications / Q000532:radiotherapy* / Q000601:surgery; D003131:Combined Modality Therapy; D006801:Humans; D007010:Hyponatremia / Q000209:etiology*; D007037:Hypothyroidism / Q000209:etiology*; D008297:Male; D009055:Mouth / Q000601:surgery; D011878:Radiotherapy / Q000009:adverse effects*; D013524:Surgical Flaps; D013974:Thyroxine / Q000627:therapeutic use; D014062:Tongue Neoplasms / Q000150:complications / Q000532:radiotherapy* / Q000601:surgery
chemical_list: D013974:Thyroxine