2.What do you think were the serum T3,T4, and TSH levels in the previous consult? What do you call this condition? – Normal levels of T3, T4 and TSH levels – Diffuse Nontoxic (Simple) Goiter Enlargement of the thyroid gland in the absence of nodules and hyperthyroidism Commonly caused by iodine deficiency Caused by exposure to environmental goitrogens such as cassava root, which contains a thiocyanate; vegetables of the Cruciferae family (e.g., brussels sprouts, cabbage, and cauliflower); and milk from regions where goitrogens are present in grass

Thyroid enlargement reflects a compensatory effort to trap iodide and produce sufficient hormone under conditions in which hormone synthesis is relatively inefficient – TSH levels are usually normal or only slightly increased, suggesting increased sensitivity to TSH or activation of other pathways that lead to thyroid growth It is more common in women than men, probably because of the greater prevalence of underlying autoimmune disease and the increased iodine demands associated with pregnancy

CLINICAL MANIFESTATIONS If thyroid function is preserved, most goiters are asymptomatic – Goiter is defined, somewhat arbitrarily, as a lateral lobe with a volume greater than the thumb of the individual being examined If the thyroid is markedly enlarged, it can cause tracheal or esophageal compression

Symmetrically enlarged, nontender, generally soft gland without palpable nodules

Substernal goiter – May obstruct the thoracic inlet – Respiratory flow measurements and CT or MRI should be used to evaluate substernal goiter in patients with obstructive signs or symptoms Pemberton's sign – Symptoms of faintness with evidence of facial congestion and external jugular venous obstruction when the arms are raised above the head, a maneuver that draws the thyroid into the thoracic inlet

DIAGNOSIS Thyroid function tests – Should be performed in all patients with goiter to exclude thyrotoxicosis or hypothyroidism – It is not unusual, particularly in iodine deficiency, to find a low total T 4, with normal T 3 and TSH, reflecting enhanced T 4 T 3 conversion

Thyroid scanning – Not generally necessary but will reveal increased uptake in iodine deficiency Ultrasound – Not generally indicated in the evaluation of diffuse goiter unless a nodule is palpable on physical examination

TREATMENT Iodine or thyroid hormone replacement – Levothyroxine Younger patients – 100 mcg/d and adjusted to suppress the TSH into the low– normal but detectable range Elderly patients – Should be initiated at 50 mcg/d The efficacy of suppressive treatment is greater in younger patients and for those with soft goiters. Significant regression is usually seen within 3–6 months of treatment

Surgery – Rarely indicated for diffuse goiter Exceptions include documented evidence of tracheal compression or obstruction of the thoracic inlet, which are more likely to be associated with substernal multinodular goiters – Subtotal or near-total thyroidectomy for these or cosmetic reasons should be performed by an experienced surgeon to minimize complication rates, which occur in up to 10% of cases – It should be followed by mild suppressive treatment with levothyroxine to prevent regrowth of the goiter

Radioiodine – Reduces goiter size by about 50% in the majority of patients – Rarely associated with transient acute swelling of the thyroid, which is usually inconsequential unless there is severe tracheal narrowing. – If not treated with levothyroxine, patients should be followed after radioiodine treatment for the possible development of hypothyroidism

3.What is your diagnosis? – Thyrotoxicosis secondary to the overdosage of L thyroxine Thyrotoxicosis – Is the state of thyroid hormone excess