Parathyroid Part 1

Question 1

Where are the Parathyroid glands and how many of them are there?

Answer 1

On the back of the Thyroid = 4 glands

Question 2

What are the 3 cell types that are within a normal Parathyroid Gland?

Answer 2

Chief Cells
Oxyphil Cells
Adipocytes

Question 3

What cell type in the Parathyroid Gland is central, round and has light pink/white cytoplasm with lots of secretory granules?

Answer 3

Chief cells

Question 4

What cell type in the Parathyroid Gland is smaller with darker nuclei and eosinophilic secretory granules?

Answer 4

Oxyphil Cells

Question 5

Which cell type in the Parathyroid gland is more pink and secretes less material?

Answer 5

Oxyphil Cells

Question 6

What is the main function of the Parathyroid glands?

Answer 6

Calcium Homeostasis

Question 7

What is the main function of the Parathyroid Glands?

Answer 7

Calcium Homeostasis

Question 8

What receptor on the Parathyroid Gland cells can measure Calcium?

Answer 8

CaSR = calcium sensing receptor

Question 9

Parathyroid Glands secrete PTH, to what sources?

Answer 9

Bone

Kidney

Question 10

PTH effect on bone?

Answer 10

Bone releases calcium to raise its levels

Question 11

What 2 things does PTH cause to occur at the kidney?

Answer 11

• Calcium reabsorption and NOT phosphate reabsorption

- Converts 25(OH)D –> 1,25(OH)2D to further mobilize calcium

Question 12

If there is LOW calcium sensed, what happens?

Answer 12

Increased PTH will be released

Question 13

If there is HIGH calcium sensed, what happens?

Answer 13

Less PTH will be released

Question 14

The normal value for calcium is around what values?

Answer 14

9-10

Question 15

What are the manifestations of Primary Hyperparathyroidism?

Answer 15

Bones
Stones - kidney
Groans - abdominal pain
Moans - psychic

Question 16

Osteoporosis and Osteitis Fibrosis Cystic are manifestations of Primary Hyperparathyroidism. What is the latter?

Answer 16

Osteoclast driven bone destruction that causes hemorrhage, fractures and the formation of brown tumors that look metastatic

Question 17

Abdominal groans with Primary Hyperparathyroidism are due to?

Answer 17

Constipation or Gallstones

Question 18

Psychic moans with Primary Hyperparathyroidism are due to?

Answer 18

Depression
Lethargy
Seizures

Question 19

What are the symptoms of Primary Hyperparathyroidism due to?

Answer 19

CHRONIC hypercalcemia

Question 20

In real life, how is Primary Hyperparathyroidism noticed?

Answer 20

LAB WORK

– routine lab work catches elevated calcium and then further workup catches elevated PTH

Question 21

What are 3 causes of Primary Hyperparathyroidism?

Answer 21

1. Adenoma
2. Primary Hyperplasia
3. Parathyroid Carcinoma

Question 22

What is the most common cause of Primary Hyperparathyroidism?

Answer 22

Parathyroid Adenoma - Benign

Question 23

How many glands are affected with Parathyroid Adenomas?

Answer 23

Usually just 1

Question 24

What is a Parathyroid Adenoma?

Answer 24

Benign, well circumscribed neoplasm of chief or oxyphil cells

Question 25

What mutation can be present with Parathyroid Adenomas?

Answer 25

MEN1 | -- germline or sporadic

Question 26

Germline mutations are present where?

Answer 26

In ALL tissues

Question 27

What will a Technetium scan show with a Parathyroid Adenoma?

Answer 27

Disproportionate area of increased uptake that localized to 1 gland

Question 28

How many glands are affected with Primary Hyperplasia?

Answer 28

ALL OF THEM

Question 29

With a Parathyroid adenoma and primary hyperplasia, what will be present around them both?

Answer 29

Normal parathyroid tissue rim

Question 30

What is the most telltale sign of a Parathyroid Carcinoma?

Answer 30

Metastasis | -- Angioinvasion and/or Adjacent tissue invasion

Question 31

With the causes of Primary Hyperparathyroidism, you can measure PTH after surgery to see if it is decreasing as normal. If it is NOT decreasing.. what is likely the cause?

Answer 31

Parathyroid Carcinoma

Question 32

Levels of Calcium and PTH with Primary Hyperparathyroidism?

Answer 32

HIGH

Question 33

What causes Hypercalcemia of Malignancy?

Answer 33

Malignancy causing elevated calcium that is NOT parathyroid related

Question 34

Levels of Calcium and PTH with Hypercalcemia of Malignancy?

Answer 34

HIGH calcium | LOW PTH

Question 35

When compared to Hyperparathyroidism, how do the symptoms present with Hypercalcemia of Malignancy?

Answer 35

More likely to be SYMPTOMATIC with Hypercalcemia of Malignancy

Question 36

In general, which is asymptomatic and which is symptomatic - Primary Hyperparathyroidism vs. Hypercalcemia of Malignancy?

Answer 36

Symptomatic = Hypercalcemia of Malignancy

Question 37

What are the symptoms that will present with Hypercalcemia of Malignancy?

Answer 37

N/V Mental status changes SHORTENED QT interval

Question 38

Mental status changes, N/V and a shortened QT interval... what are you thinking it could be?

Answer 38

Hypercalcemia of Malignancy

Question 39

Squamous Carcinomas and Lymphomas can both cause Humoral Hypercalcemia of Malignancy. What do they secrete?

Answer 39

``` Squamous = PTHrP Lymphomas = Vitamin D ```

Question 40

Breast Carcinomas and Myelomas can cause Local Osteolytic Hypercalcemia of Malignancy. What do they do?

Answer 40

Cause elevated calcium from direct osteoclastic resorption