All of the following are true about Hashimoto's thyroiditis except:
. Ans. d. Orphan Annie eye nuclei Orphan Annie eye nuclei is seen in papillary carcinoma thyroid.Histological characteristics of Papillary Carcinoma Thyroid* Papillary projections: PTC contains branching papillae of cuboidal epithelial cells* Orphan Annie eye nuclei:The nuclei contain finely dispersed chromatin, which imparts an optically clear or empty appearance, giving rise to term ground glass or Orphan Annie eye nuclei.Invaginations of cytoplasm in cross-sections: Intranuclear inclusions** (pseudo-inclusion) or intranuclear grooves.Diagnosis of PTC is based on these nuclear characteristics9 even in the absence of papillary structures.* Psammoma bodies: Microscopic, calcified deposits representing clumps of sloughed cellsHashtmoto's Thyroiditis* First described by Hashimoto as struma lymphomatosa i.e. a transformation of thyroid tissue to lymphoid tissue.* MC inflammatory disorder of the thyroid and leading cause of hypothyroidism.Thyroid lymphoma is a rare but well recognized complicationPapillary thyroid carcinoma may be occasionally associated* Genetic association has been noted with HLA B8, DR3 and DR59.* More common in women (Male: female, 1:10), near menopause (30-50 years).Etiopathogenesis:* Autoimmune disease* Thought to be initiated by activation of CD4+T (helper) lymphocytes, which further recruit cytotoxic CD8+T cells.Hashimoto's Thyroiditis* Thyroid tissue is destroyed by cytrotoxic T cells and autoantibodies0.Autoantibodies are directed against1. Thyroglobulin (Tg): 60%2. Thyroid peroxidase (TPO): 95%3. TSH-R: 60%* It is also thought to be associated with:Increased intake of iodineDrugs such as interferon alpha, lithium, amiodaronePathology:* Gross examination: Mildly enlarged thyroid0 with pale, gray-tan cut surface* Microscopic examination:- Gland is diffusely infiltrated by small lymphocytes and plasma cellsQ and occasionally shows well-developed germinal centers.- Smaller thyroid follicles with reduced colloid and increased interstitial connective tissue.- Follicles are lined by Hiirthle or Askanazy cells0 (characterized by abundant eosinophilic, granular cytoplasm)Clinical Features:* MC presentation: Minimally or moderately enlarged firm gland0.* On examination an enlarged pyramidal lobe is often palpable.* Mild hyperthyroidism may be present initially (due to destruction of thyroid tissue)* Hypothyroidism is inevitable and usually permanent0.Laboratory findings:* Elevated TSH and presence of thyroid autoantibodies confirm the diagnosis0.* Elevated TSH. reduced T4 and T3 levels0.Presence to thyroid autoantibodies (particularly TPO antibody)0* In case of doubt, diagnosis is confirmed by F.NA biopsy.Management:* Thyroid hormone replacement therapy for overtly hypothyroid patients or in euthyroid patients to shrink large goiters.* Treatment is advised especially for middle-aged patients with cardiovascular risk factors such as hyperlipidemia or hypertension and in pregnant patients.* Surgery may occasionally be indicated for suspicion of malignancy or for goiters causing compressive symptoms or cosmetic deformity.
Follicular destruction
Increase in lymphocytes
Oncocytic metaplasia
Orphan Annie eye nuclei
Disorders of Thyroid Metabolism