B6.050 Post CBCL Formative Info

Question 1

what are reasons you might expect a rare parathyroid carcinoma?

Answer 1

palpable neck mass
hypercalcemia > 14 mg/dL
parathyroid adenoma and hyperplasia do not present as palpable masses

Question 2

histology of a parathyroid malignancy

Answer 2

marked mitotic activity, dense fibrous stroma, evidence of local invasion into capsule or surrounding vessels
metastasis most common to lymph nodes

Question 3

histology of parathyroid hyperplasia

Answer 3

diffuse proliferation of clear cells with little remaining normal tissue

Question 4

histology of parathyroid adenoma

Answer 4

single focus of chief cells, surrounded by a compressed rim of normal tissues

Question 5

first sign of MEN 1

Answer 5

parathyroid adenomas and 4 gland hyperplasia
presents with increased PTH and Ca
typically in 3rd or 4th decade w no gender predilection

Question 6

symptoms of hypercalcemia in MEN 1 patients

Answer 6

involve urinary tract rather than the skeleton

many are asymptomatic

Question 7

treatment of MEN 1 parathyroid disease

Answer 7

3. 5 gland (subtotal) resection

goal: achieve normocalcemia for as long as possible while avoiding hypoparathyroidism

Question 8

other tumors associated with MEN 1

Answer 8

pancreatic endocrine tumors
pituitary tumors
thymic carcinoids

Question 9

pancreatic tumors in MEN 1

Answer 9

gastrinoma (Zollinger Ellison, PUD and diarrhea)
insulinomas
VIPomas
glucagonomas

Question 10

pituitary tumors in MEN 1

Answer 10

prolactin

GH

Question 11

mutation in MEN 1

Answer 11

MENIN tumor suppressor on chromosome 11

Question 12

significance of lithium induced HPTH

Answer 12

more likely to need a 4 gland exploration since all 4 glands are exposed to the effects of lithium
higher tendency to cause 4 gland hyperplasia than in the normal population

Question 13

3 Ps of MEN 1

Answer 13

parathyroid
pancreas
pitutitary

Question 14

describe pseudohypoparathyroidism

Answer 14

target tissue resistance to PTH
low serum calcium
elevated serum PO4
defect in skeletal growth and development

Question 15

disorder associated with pseudohypoparathyroidism

Answer 15

mutations in GNAS1

PTH function is normal, but kidney cannot respond to PTH stimulation due to loss of functional signaling pathway

Question 16

additional surgery in MEN 1 parathyroid disease

Answer 16

bilateral thymectomy

patients have a greater incidence of thymic carcinoids as well as ectopic parathyroid glands

Question 17

when you resect a parathyroid gland that you thought was the cause of HPTH, and the PTH doesn’t go down, what do you do?

Answer 17

check ipsilateral gland next
if adenomatous, resect this one too
if PTH still doesn’t drop, move to contralateral side and do a total parathyroidectomy
auto implantation follows

Question 18

EKG finding with hypocalcemia

Answer 18

prolonged QT interval

T wave inversion

Question 19

treatment for severe hypocalcemia

Answer 19

IV 10% calcium gluconate to achieve serum conc of 7-9 mg/dL

also correct associated deficits in Mg, K, and pH

Question 20

how does severe hypomagnesemia perpetuate hypocalcemia

Answer 20

low Mg can suppress PTH release

low Mg can stimulate osteoblastic activity

Question 21

how does modest hypomagnesemia perpetuate hypocalcemia

Answer 21

impair end organ response to PTH

Question 22

earliest clinical feature of hypocalcemia

Answer 22

numbness

tingling in circumoral region or tips of fingers

Question 23

profound clinical features of hypocalcemia

Answer 23

tetany
seizure
Trousseau sign
Chvostek’s sign

Question 24

where is calcitonin produced

Answer 24

perifollicular C cells of thyroid

Question 25

when would calcitonin be elevated

Answer 25

medullary thyroid carcinoma

Question 26

functions of calcitonin

Answer 26

decreases BOTH serum concentrations of Ca and PO4
inhibits osteoclasts
stimulates osteoblasts

Question 27

when is calcitonin used

Answer 27

treatment of hypercalcemic crisis