Thyroid Gland Pathology Flashcards Preview

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Flashcards in Thyroid Gland Pathology Deck (46):
1

What are the cells lining the follicle?

Cuboidal or Columnar Epithelium

2

What do C cells secrete?

Calcitonin

3

What is the function of calcitonin

Calcitonin promotes absorption of calcium by the skeletal system and inhibits resorption of bone by osteoclasts

4

Thyrotoxicosis

Hyper metabolic state due to increased circulating levels of thyroid hormones due to any cause - often used interchangeably with hyperthyroidism

5

How does thyroiditis cause hyperthyroidism?

Destruction of the glands leads to release of pre-formed hormone that causes transient hyperthyroid episodes

6

What are the clinical features of hyperthyroidism?

• Increased BMR – soft warm flushed skin
• Heat intolerance and excess sweating
• Characteristic weight loss despite increased appetite
• Increased CO/tachycardia/palpitations

7

What tests can be used for Dx of hyperthyroidism?

- TSH levels - usually will be decreased
- T4 levels - usually increased

8

What is the TRH stimulation test used for?

Pituitary adenoma - normal rise in TSH after injection
of TRH excludes pituitary associated hyperthyroidism

9

Hypothyroidism

Hypometabolic state secondary to inadequate levels of thyroid hormones

10

What gender is more affected by hypothyroidism?

Females

11

What is the most common cause of hypothyroidism in 3rd world countries?

Iodine Deficiency

12

What is the most common cause of hypothyroidism in 1st world countries?

Chronic autoimmune thyroiditis (Hashimoto’s thyroiditis)

13

Cretinism

• Hypothyroidism in infants or early childhood
• Impaired development of skeletal muscles and CNS

14

Myxedema

• Adult hypothyroidism
• Gradual slowing of mental and physical activity
• Fatigue, lethargy, apathy, slowed speech
• Cold intolerance and reduced sweating

15

What lab findings with hypothyroidism show?

- Decreased T4
- Increased TSH

16

Hashimoto Thyroiditis

Characterized by gradual thyroid failure because of autoimmune destruction of the thyroid gland

17

What Ab will be found in Hashimoto thyroiditis?

- Thyroid Peroxidase Ab
- Thyroglobulin Ab
- TSH Receptor Ab
- Iodine Receptor Ab

18

•Diffusely enlarged gland
•Intact capsule
•Well demarcated from adjacent structures
•Cut surface is pale, yellow tan, somewhat nodular and firm

Hashimoto Thyroiditis

19

What cancer risk is increased with Hashimoto thyroiditis?

Non-Hodgkin B-cell Lymphoma

20

Subacute/Granulomatous DeQuervain Thyroiditis

• Viral or post-viral inflammatory response
• Viral antigens or virus-induced host tissue damage stimulates formation of cytotoxic T cells which then damage the thyroid follicular cells

21

What is the most common cause of thyroid pain?

Subacute/Granulomatous DeQuervain Thyroiditis

22

Subacute Lymphocytic Thyroiditis

- Usually in middle aged women and is painless
- Comes to clinical attention due to mild hyperthyroidism, goitrous enlargement of the thyroid or both

23

Riedel Thyroiditis

RARE - Extensive fibrosis involving the thyroid and contiguous neck structures with possible autoimmune etiology

24

What is the most common cause of endogenous hyperthyroidism?

Graves Disease

25

Graves Disease

Hyperthyroidism due to diffuse hyperfunctional enlargement of thyroid with signs: exophthalmos and pretibial myxedema

26

What are the Ab found in Graves disease?

Thyroid stimulating immunoglobulin - binds TSH receptor with agonist function and mimics action of TSH

27

What is increased radioactive iodine uptake with diffuse uptake on radio iodine scans indicative of?

Graves Disease

28

Goiter

Enlargement of the thyroid

29

Diffuse Nontoxic Goiter

- Vast majority of patients euthyroid
- Mass effect – large thyroid may press on trachea, esophagus and also cause cosmetic disfigurement
- Normal T4 and T3

30

Multinodular Goiter

- Asymmetric enlargement with numerous nodules
- Seen in older adults
- Evolvement from diffuse goiters over many years due to repeated episodes of hyperplasia and involution from cyclical stressors

31

Nodules in what patients are more likely to be neoplasia?

- Males
- Younger patients

32

Follicular Adenoma

Benign - well defined in tact capsule with small follicles that are tightly packed

33

Follicular adenoma with cells bearing abundant pink granular cytoplasm due to presence of abundant mitochondria.

Oxyphil Adenoma

34

What is the most common thyroid carcinoma?

Papillary Carcinoma

35

What are histologic characteristics of papillary carcinoma?

- Ground glass or Orphan Annie eyed nuclei
- Large oval nuclei
- Psamomma bodies

36

Are papillae see with FVPTC?

No - follicular variant papillary thyroid carcinoma presents with follicular architecture

37

What mutation is associated with papillary carcinoma?

RET

38

Follicular Carcinoma

- Second most common thyroid cancer
- Slowly enlarging painless nodule – cold on scintiscans
- Hematogenous metastasis to bone, lungs, liver etc
- Capsular or vascular invasion

39

- Neuroendocrine neoplasms derived from the parafollicular or C cells
- May secrete calcitonin or other polypeptide hormones like ACTH or VIP
- 70% sporadic, 30% familial or associated with MEN syndrome 2A or 2B

Medullary Carcinoma

40

What is deposited in medullary carcinoma?

Amyloid

41

Anaplastic Carcinoma

Undifferentiated tumors that are aggressive with poor prognosis - Usually the disease has spread beyond thyroid into adjacent structures of the neck at presentation

42

Thyroglossal Duct Cyst

- Most common clinically significant congenital anomaly
- Incomplete atrophy of the duct
- Presents at any age as a midline cyst or an anterior mass

43

A 49-year-old woman has had increasing cold intolerance, weight gain of 4 kg, and sluggishness over the past two years. A physical examination reveals dry, coarse skin and alopecia of the scalp. Her thyroid is not palpably enlarged. Her serum TSH is 11.7 UU/mL (ref range 0.4 -4.4 uu/ml) with thyroxine of 2.1 ug/dL (ref range 5-11 ug/dL). A year ago, anti-thyroglobulin and anti-microsomal autoantibodies were detected at high titer. Which of the following thyroid diseases is she most likely to have?

A) DeQuervain disease
B) Papillary carcinoma
C) Hashimoto thyroiditis
D) Nodular goiter
E) Graves disease

C) Hashimoto thyroiditis

44

A 40-year-old woman notes increasing enlargement and discomfort in her neck over the past week. She sees her physician, who palpates diffuse, symmetrical enlargement with tenderness in the region of the thyroid gland. Thyroid function tests show serum TSH of 0.8 mUU/mL (ref range 0.4 -4.4 UU/ml) and thyroxine of 14.9 ug/dL (ref range 5-11 ug/dl). The physician refers the patient to an endocrinologist, but the next available appointment is in 8 weeks. When the endocrinologist examines the patient, the thyroid is no longer palpable and there is no pain. Repeat thyroid function tests reveal a serum TSH of 3.8 UU/mL and thyroxine of 5.7 ug/dL. Which of the following thyroid diseases is most likely to produce these findings?

A) Nodular goiter
B) Non-Hodgkin lymphoma
C) DeQuervain disease
D) Hashimoto thyroiditis
E) Graves disease
F) Riedel thyroiditis

C) DeQuervain disease

45

A 35-year-old woman has had insomnia for the past 4 months. She has also had episodes of diarrhea with up to 4 loose stools per day. On physical examination, she exhibits bilateral lid lag and wide staring gaze. Her outstretched hands demonstrate a fine tremor. On palpation of her neck, the thyroid gland does not appear to be enlarged and no masses are palpable. Laboratory studies show a serum TSH of 10.8 UU/mL (ref range 0.4-4.4 UU/ml) in association with a serum free thyroxine of 5.1 ng/dL (ref range 0.8-1.7 ng/dl). Which of the following is the most likely diagnosis?

A) Graves disease
B) Pituitary adenoma
C) Chronic thyroiditis
D) Prior thyroidectomy
E) Nodular goiter

B) Pituitary adenoma

46

A 30-year-old woman from Barcelona has noted enlargement of her neck over the past 4 months. On physical examination, she has a diffusely enlarged thyroid that is not painful to palpation. Her TSH level is 0.2 mU/L. A subtotal thyroidectomy is performed and histologically the tissue shows follicles with papillary infoldings lined by tall columnar cells. Which of the following is the most likely diagnosis?

A) Subacute granulomatous thyroiditis
B) Papillary carcinoma
C) Multinodular goiter
D) Hashimoto thyroiditis
E) Graves disease

E) Graves disease

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