Path of the Parathyroid

Question 1

What are the three major pathologies of parathyroid disease?

Answer 1

• Hyperparathyroidism
• Parathyroid CA
• Hypoparathyroidism

Question 2

What is the most common cause of hyperparathyroidism?

Answer 2

Parathyroid adenoma

Question 3

What defines PTH secreting adenomas (where, character)?

Answer 3

Lesions within the parathyroid gland that are not inhibited by elevated Ca levels

Question 4

Excess PTH causes what? Why (4)?

Answer 4

Hypercalcemia:

• Increase bone resorption
• Increase renal reabsorption
• Increase urinary excretion of phosphate
• Increase renal Vit D synthesis

Question 5

Why is there still calciuria in hyperparathyroidism, when PTH increases Ca reabsorption?

Answer 5

Filtered load of Ca is so high

Question 6

What kidney pathology can be caused by hyperparathyroidism? Why?

Answer 6

• Renal calculi

- Ca load so high, filtered out in high loads

Question 7

What are the four major ssx of hyperparathyroidism?

Answer 7

• Stones
• Bones (osteomalacia)
• Groans (Gastrin release causes PUD)
• Moans (Mental changes)

Question 8

What is the “groans” part of the ssx of hyperparathyroidism?

Answer 8

PTH induces gastrin release, causing PUDs

Question 9

What are brown tumors?

Answer 9

Osteitis fibrosa cystica–replacement of bone with fibrous tissue 2/2 loss of Ca from hyperparathyroidism

Question 10

What is the most common presentation of hyperparathyroidism?

Answer 10

Abdominal pain 2/2 PUD formation

Question 11

In whom are parathyroid adenomas common?

Answer 11

Older women

Question 12

What is the weight of parathyroid adenomas?

Answer 12

1 g

Question 13

True or false: parathyroid adenomas are usually solitary, single lesions

Answer 13

True

Question 14

What is the usual size of parathyroid glands (summed together)?

Answer 14

20-40 mg

Question 15

What percent of parathyroid adenomas are in an ectopic location?

Answer 15

10%

Question 16

What is the imaging modality that allows for easy visualization of parathyroid adenomas?

Answer 16

Sestamibi nuclear imaging

minimally invasive radioguided parathyroidectomy (MIRP

Question 17

What is MIRP?

Answer 17

Minimally invasive radioguided parathyroidectomy–radioactive sestamibi that is preferentially absorbed by parathyroid adenomas

Question 18

Where are most ectopic parathyroid adenomas found?

Answer 18

Mediastinum

Question 19

What are the gross findings of a parathyroid adenoma?

Answer 19

Solitary, well circumscribed, tan-reddish brown nodules invested by a delicate capsule

Question 20

Are parathyroid adenomas usually encapsulated?

Answer 20

Yes

Question 21

What defines a parathyroid carcinoma?

Answer 21

Adenoma that pierces the capsule

Question 22

What are the histological characteristics of a parathyroid adenoma? (3)

Answer 22

• No fat cells
• Primarily chief cells
• Thin rim of normal parathyroid tissue

Question 23

What are the histological characteristics of the cells in parathyroid adenomas?

Answer 23

Chief cells with small, centrally placed nuclei with slight variation in nuclear size

Question 24

What is the second most common etiology of primary hyperparathyroidism?

Answer 24

Parathyroid hyperplasia

Question 25

What are the gross characteristics of parathyroid hyperplasia?

Answer 25

All 4 glands are big (unlike adenomas)

Question 26

How can you differentiate parathyroid hyperplasia vs an adenoma?

Answer 26

Adenoma is a single solitary lesions, whereas hyperplasia

Question 27

True or false: Parathyroid hyperplasia maintains the fat cells that the glands usually have

Answer 27

False--usually lack them

Question 28

What is the most common cause of parathyroid hyperplasia?

Answer 28

MEN syndromes

Question 29

How can you differentiate parathyroid hyperplasia vs adenoma?

Answer 29

Adenomas have a rim of parathyroid tissue Hyperplasia has NO rim of normal parthyroidtissue

Question 30

What is secondary hyperparathyroidism?

Answer 30

Due to hypocalcemia from some other cause

Question 31

What is the most common cause of secondary hyperparathyroidism?

Answer 31

Chronic renal failure causing low Ca

Question 32

What is the most common type of tumor that produces calcitonin?

Answer 32

Medullary carcinoma of the thyroid

Question 33

What, besides CRF, can cause secondary hyperparathyroidism?

Answer 33

Malabsorption or nutritional deficit

Question 34

What is renal osteodystrophy? How do you treat this (2)?

Answer 34

Renal losses of Ca causes hyperparathyroidism -Exogenous Calcitriol or partial parathyroidectomy

Question 35

Is the malignant potential of parathyroid carcinoma high or low? What about recurrence rate?

Answer 35

Low malignant potential, but high recurrence rates

Question 36

What is the treatment for parathyroid carcinoma?

Answer 36

50% cured by en bloc resection

Question 37

Where do parathyroid CAs metastasize to? Is this fast or slow

Answer 37

Lymphatic and hematogenous, but this is slow

Question 38

What are the histological characteristics of parathyroid CA?

Answer 38

Thick, fibrous bands

Question 39

Thick fibrous bands on a parathyroid sample = ?

Answer 39

Parathyroid carcinoma

Question 40

What is the gross appearance of a parathyroid carcinoma?

Answer 40

Gray-white irregular mass that may exceed 10 g in weight

Question 41

Do the cells in parathyroid carcinoma resemble normal parathyroid cells? How are they arranged?

Answer 41

Resemble normal cells, but are arranged in thick, fibrous bands

Question 42

True or false: histological examination of parathyroid glands is the a reliable diagnostic tool for parathyroid carcinoma

Answer 42

False--the only reliable criteria is if there is invasion of surrounding tissue and mets

Question 43

What is the most common cause of hypoparathyroidism?

Answer 43

Autoimmune disorder

Question 44

What is the most common acquired cause of hypoparathyroidism?

Answer 44

DiGeorge syndrome chr 22 del and failure of the 3rd and 4th pharyngeal pouch

Question 45

What are the ssx of hypoparathyroidism?

Answer 45

- metal changes | - circumoral paresthesia

Question 46

What are the end stages of hypoparathyroidism?

Answer 46

Convulsions and tetany

Question 47

How do you diagnose hypoparathyroidism?

Answer 47

Decreased serum [Ca] and increases serum [phosphate]

Question 48

What is the treatment for hypoparathyroidism?

Answer 48

- Vit D - Ca gluconate cookies - Recombinant human PTH