Thyroid gland References 1Robbins Basic Pathology 2Pathology outlines Learning objectives 1 Thyroiditis 2 Goiter 3 Neoplastic lesions of the thyroid gland Thyroid diseases Hyperthyroidism ID: 1044858
Download Presentation The PPT/PDF document "Dr. Noor Sabeeh 2021/2022" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
1. Dr. Noor Sabeeh2021/2022 Thyroid gland References:1.Robbins Basic Pathology2.Pathology outlines
2. Learning objectives 1. Thyroiditis .2. Goiter3. Neoplastic lesions of the thyroid gland
3.
4. Thyroid diseases
5.
6. Hyperthyroidism:Thyrotoxicosis is a hypermetabolic state caused by elevated circulating levels of free T3 and TThe three most common causes of thyrotoxicosis are :• Diffuse hyperplasia of the thyroid associated with Graves disease • Hyperfunctioning (“toxic”) multinodular goiter • Hyperfunctional (“toxic”) adenoma of the thyroid
7. Hypothyroidismcaused by structural or functional derangements that interfere with thyroid hormone productionCauses:Genetic defects (thyroid dysgenesis) or (dyshormonogenetic goiter) Endemic deficiency of dietary iodine Autoimmune thyroid disease (Hashimoto thyroiditis ) Iatrogenic hypothyroidism can be caused by either surgical or radiation-induced ablation of thyroid gland.The clinical manifestations of hypothyroidisms are CretinismMyxedema
8. CretinismHypothyroidism developed in infancy or early childhood , either due to dietary iodine deficiency or enzymatic defect Myxedema Hypothyroidism developed in older children and adults
9. Thyroiditis is a general term that refers to “inflammation of the thyroid gland”. it includes a group of individual disorders causing thyroid inflammation but presenting in different ways. Some conditions cause acute illness and sever thyroid pain e.g. infectious thyroiditis, and others with a relatively little inflammation but manifested by thyroid dysfunction
10. It is the most common cause of goitrous hypothyroidism in iodine sufficient areas . Characterized by painless gradual thyroid failure because of autoimmune destruction of the thyroid gland. May associated with other autoimmune diseases as (SLE, type II diabetes, rheumatoid arthritis)May evolved into thyroid lymphoma
11. Grossly Diffuse symmetric enlargement of thyroid glandMicroscopically Extensive lymphocytic infiltrate lymphoid follicles with germinal center formationFibrosis
12. Inflammation of thyroid gland that includes granulomas formation Rare, much less common than Hashimoto thyroiditisCaused by viral infection Presented with thyroid pain, it is self limited disease
13. Commonest cause of endogenous hyperthyroidism with a Female predominance It an autoimmune disease in which circulating autoantibodies against thyrotropin (TSH receptor) that activates the receptor, leading to increased thyroid hormone synthesis and secretion other autoimmune disease such as SLE, pernicious anemia, type I DM
14. ThyrotoxicosisExophthalmosDermopathy (pretibial myxedema)Characterized by triad of manifestations:
15. Goiter is enlargement of the thyroid gland which is the most common manifestation of thyroid disease. It reflect impaired synthesis of thyroid hormones, which is most often caused by dietary iodine deficiency. Impairment of thyroid hormone synthesis leads to a compensatory rise in the serum TSH level, which, in turn, causes hypertrophy and hyperplasia of thyroid follicular cells lead to gross enlargement of the thyroid gland.
16. simple goiter .
17. Virtually all long-standing simple goiters convert into multinodular goiters with recurrent episodes of hyperplasiaIt is hormonally silent ,thyrotoxicosis secondary to the development of autononmus nodules that produce thyroid hormone (toxic MNG) Risk of malignancy is low
18. Multinodular goiter
19. Thyroid neoplasm ranging from benign adenoma to highly aggressive ca. several clinical criteria provide a clue to the nature of thyroid nodule:1.Solitary nodule neoplastic2.Nodule in younger patients neoplastic3.Nodule in male neoplastic 4.A history of radiation to head and neck carcinoma.5.Hot nodule that take up iodine in imaging neoplastic
20. Benign tumor of thyroid derived from follicular epithelium Clinically, follicular adenomas difficult to distinguish from other causes of solitary thyroid nodule which could be (simple goiter, dominant nodule of multinodular goiter, thyroid cyst, foci of thyroiditis and follicular carcinoma ) only by careful histopatholgical examination Mainly nonfunctional, a small proportion produces thyroid hormones and causes thyrotoxicosis.
21. Morphology. Solitary, tan-light brown encapsulated massWell demarcated from the adjacent thyroid tissue by a well-defined, intact capsule.
22. Microscopically Uniform follicles contain colloid lined by benign cuboidal or columnar epithelium.Intact, well-formed capsule encircling the tumorcolloidfolliclesTumor massIntact tumor capsuleNormal thyroid tissue
23. Papillary carcinoma (>85%)2. Follicular carcinoma 3. Hurthle cell carcinoma4. Anaplastic (undifferentiated) carcinoma5. Medullary carcinoma . arise from parafollicular C cells. neuroendocrine tumor secreting calcitonin hormoneMost thyroid carcinomas (except medullary carcinomas) are derived from the thyroid follicular epithelium
24. Most common form of thyroid cancer.. It associated with previous exposure to ionizing radiation before the age of 20Mostly present as asymptomatic thyroid noduleTendency to spread to regional lymph nodes
25. Microscopically Papillae having a fibrovascular stalk. The diagnosis of papillary carcinoma is made based on the nuclear features
26. The nuclei of papillary carcinoma cells with chromatin clearing / optically clear chromatin glassy / ground nuclei, (Orphan Annie nuclei)
27. Common in areas with dietary iodine deficiencyMicroscopically Small follicles containing colloidCapsular invasion with invasion to adjacent thyroid tissue