Hyperthyroidism This disease result from an excess of circulating thyroid hormone.that may arise from a number of condition(graves disease,drug induced,thyroiditis,thyroid cancer…) its very important to distinguish disorders: 1.Cause excess production of hormone such as graves disease from 2.An other condition which release stored hormone such as thyroiditis. First disorder characterized by increasing in radioactive iodine uptake.
Diffuse toxic Goiter(Graves disease) Its an autoimmune disease with a strong familial predisposition.there is a high incidence in female especially between 40_60 years. the exact etiology of this disease is not known but some condition such as iodine excess,lithium therapy,bacterial & viral infection…suggested as triggers.genetic factor especially present of HLADQA1.0501,HLADR3,HLAB8 also play important role. The clinical manifestation of graves disease divided into 2category: 1.those related to hyperthyroidism & 2.those specific to Graves disease. Hyperthyroid symptom include:heat intolerance,incresed sweating & thirst,weight loss,palpitation,fatigue,diarrhea,increased incidence of miscarriages,…
Nearly 50% of patiant have ophthalmopathy & 1 to 2% have dermopathy.eye symptoms include lid lag(von graefes sign),spasm of upper eyelid revealing the sclera(dalrymple sign),conjunctival swelling & congestion(chemosis)… Diagnostic tests: the diagnosis of hyper thyroidism is made by a suppressed TSH with or without an elevated free T4 or T3 level.but if eye sign are present other tests are not needed.in patient with out eye sign (I 123)uptake with diffusely enlarged gland can confirm diagnosis. Other tests including:determining T3 level(in T3 toxicosis), anti TG antibodise,TPO antibodies,TSAB Treatment: graves disease may be treated by any of 3 treatment modalities: 1.Antithyroid drugs 2.radioactive iodine therapy(RAI) 3.thyroidectomy
1.Antithyroid medications: generally are administered before RAI ablation or surgery. Drugs: Propylthiouracil(PTU) have less side effect Methimazole the proper dose of drugs depend on TSH & T4 levels. 2.Radioactive iodine therapy: This method most often used in: Older patient with small or moderate sized goiter. * Patient with relapse after medical or surgical therapy. * Those in whom 2other method are contraindicated. * Absolute contraindication: pregnancy 3.Surgical treatment Patients with coexistent thyroid cancer,those who refuse RAI therapy or have severe ophtalmopathy or have life threatening reaction to antithyroid medication should undergo surgery.
Toxic Multinodular Goiter Occur in older individuals with nontoxic multinodular goiter,over several years become autonomous and cause hyperthyroidism. Sign & diagnostic studies are similar to Graves disease. Treatment surgical + thyroid hormone suppression therapy(to prevent recurrence) RAI is recommended in patient with high risk for surgery.
Toxic Adenoma In this disease hyperfunction of single nodule cause hyperthyroidism,especially in young patients. RAI scanning shows a hot nodule with suppression the rest of thyroid gland. These nodules are rarely malignant. Treatment Small nodule need medication therapy & RAI Large nodule surgery
Thyroid storm Is condition of hyperthyroidism accompained by fever,agitation,cardiovascular dysfunction that may result from infection, surgery,or trauma. Treatment:administration of B_blocker,corticosteroid & Lugols iodine,oxygen supplemention & control of hemodynamic.
Hypothyroidism Deficiency in circulating levels of thyroid hormone lead to hypothyroidism and cause neurologic impairment and retardation in neonates(cretinism). hypothyroidism also may occur in Pendreds syndrome.(associated with deafness) and turners syndrome. In adult symptoms are non specific:weight gain,cold intolerance,constipation,dry skin,dry hair,sever hair loss…. Laboratory findings: low level of T3 &T4 In primary hypothyroidism raised TSH level In second hypothyroidism suppressed TSH level Treatment :administering T4 Dosage depend on condition of patient.
Thyroiditis Classified into acute,subacute,and chronic forms. Acute(suppurative)thyroiditis: Thyroid gland is resistant to infection but some times infectious agents can seed it Via the hematogenous * After penetrating trauma * Due to immunosuppression…… * This disease is more common in children and characterized by severe neck pain(radiating to jaws or ear),fever,chill,odynophagia,&dysphonia. The diagnosis confirm by leukocytosis on blood tests and FNAB for Grams stain,culture,and cytology. Treatment: Antibiotic + drainage of abscesses.
Subacute Thyroiditis Can occur in the painful or painless forms.exact etiology is not known but: Painful: viral infection,genetic(HLAB35) In this disease cytotoxic T lymphocytes stimulate and damage thyroid follicular cell. Its common in women,characterized by sudden or gradual onset of neck pain.the gland is large,tender & firm.(T4,T3.ESR high / TSH low The disorder progresses through 4stage: Hyperthyroidism, euthyroidism, hypothyroidism, euthyroidism. Treatment Aspirin,NSAID,thyroid hormone therapy,& some times thyroidectomy
Painless: may be an autoimmune disease and especially occur in women after delivery. symptoms and clinical course are similar to painful form. Treatment B-blocker, thyroid hormone, and some times thyroidectomy or RAI ablation
Choronic thyroiditis lymphocytic Is an autoimmune process initiated by the activation of CD4 T helper lymphocytes which destruct thyrocytes. antibodies directed against 3main Ag: Tg,TPO,TSH-R Disease is common in women between years.minimally or moderately enlarged firm granular gland discover in examination.FNAB can be useful that in pathology we see follicles lined by Ashanazy cell. Diagnostic studies: Elevated TSH and present of thyroid autoantibody confirm the diagnosis. Treatment: thyroid hormone,surgery(for suspicion of malignancy,or cosmetic deformity)
Riedels Thyroiditis Is rare variant of thyroiditis which characterized by replacement of all or part of the thyroid parenchyma by fibrous tissue.it presents as painless,hard(woody) neck mass. Symptom include: Dysphagia,dyspnea, hoarsness, choking, hypothyroidism, hypoparathyroidism… Biopsy is necessary. Treatment : surgery
Goiter Familial goiter resulting from dificiencies in enzymes necessary for thyroid hormone synthesis hypothyroidism Endemic goiter resulting from iodine deficiency and can be treated by iodine. Clinical feature:most patients are asymptomatic,although patients often complain of pressure sensation in the neck. We can find soft enlarged gland(simple goiter)or nodules of various size(in multinodular goiter) Thyroid tests are usually normal. Treatment: Patient with small,diffuse goiter do not need treatment In large goiter thyroid hormone therapy can be useful.
Solitary thyroid nodule History such as time of onset,change in size of nodule and associated symptom(pain,dysphagia,dyspnea…) is very important. We should ask from ionizing radiation and familial history of malignancy. Nodules that are hard,or fixed to surrounding structure are most likely to be malignant. Diagnostic investigations FNAB has become the most important test. After FNAB nodules can be categorized into:bening- suspicious-malignant Ultrasound is inexpensive and noninvasive method that can be helpful for detecting nonpalpable thyroid nodule,differentiating solid from cystic nodule.calcification….
Solitary Thyroid Nodule
But in patient with history of previous irradiation of thyroid gland or familial thyroid cancer, surgery should be done.