8

Question 1

medullary thyroid cancer is ??

how does it look microscopically??

Answer 1

a neuroendocrine tumor that arises from parafollicular calcitonin-secreting C cells
-nests/sheets of polygonal or spindle-shaped cells with extracellular AMYLOID deposits (from calcitonin secreted from the neoplastic C cells)
–>stain Congo red
(associated with MEN2A, MEN2B; RET mutation)

Question 2

papillary thyroid cancer microscopically??

Answer 2

papillary structures lined by cuboidal cells with large nuclei which may be pale + thin rim of chromatin (Orphan Annie nuclei)
psammoma bodies in the core of papillae as well
(RET and BRAF mutations, childhood radiation)

Question 3

anaplastic thyroid carcinoma microscopically?

Answer 3

large pleomorphic giant cells

Question 4

benign follicular adenoma

Answer 4

colloid containing microfollicles (sheets of uniform cells forming small follicles)
-similar appearance to follicular adenocarcinoma, but that will have vascular invasion often (hematogenous spread, RAS mutations)

Question 5

hereditary orotic aciduria is a defect in what enzyme??
presents how?
supplemnent pts with ??

Answer 5

defect in UMP synthase (orotic acid–>UMP) (AR disorder of de novo pyrimidine synthesis)

• phys/mental retardation, megaloblastic anemia, ^orotic acid, NO ^ammonia (in contrast to OTC def.)
• supplement sith uridine to bypass the defect (uridine–>UMP by nucleoside kinases)

Question 6

pyridoxine (B6) is a cofactor in ??

Answer 6

transamination, deamination, decarboxylation and condensation reactions

Question 7

direct arteriolar vasodilators lower BP but trigger reflex sympathetic activation and stimulate ??

Answer 7

RAAS (JG cells sense decr. in BP)
resulting in tachycardia and edema
(typically given in combo with sympatholytics (B-blockers) and diuretics)

Question 8

B-endorphin is an endogenous opioid peptide derived from ??

Answer 8

POMC; which also produces ACTH and MSH

close relationship btw stress axis and opioid system

Question 9

chronic rejection will affect what structures in lung transplant recipients ??
what will you see?

Answer 9

small airways, causing bronchiolitis obliterans

-see lymphoctic inflammation, fibrosis, and ultimately destruction of the bronchioles

Question 10

what triad seen with PNH? what will be seen in kidney?

Answer 10

hemolytic anemia (hemobglobinuria), pancytopenia, thrombosis at atypical sites
-chronic hemolysis can cause iron deposition in the kidney (hemosiderosis)

Question 11

primary vs secondary membranous nephropathy

Answer 11

primary: Abs to phospholipase A2 receptor
secondary: drugs (NSAIDs, penicillamine), infections (HBV, HCV), SLE or solid tumors

Question 12

acetyl CoA carboxylase

Answer 12

FA synthesis; converts acetyl CoA to malonyl CoA (cytosol)

Question 13

acyl CoA synthetase

Answer 13

activates FA to acyl CoA in cytoplasm, then combined w. carnitine and transported to mitochondria to undergo B-oxidation

Question 14

during FA synthesis, acetyl CoA is generated in mitochondria during glycolysis and is transferred to the cytosol as citrate
in the cytoplasm ?? converts citrate back to oxaloacetate and acetyl CoA

Answer 14

ATP citrate lyase

Question 15

drugs that cause acute interstitial nephritis

Answer 15

5 P's
Pee (diuretics)
Pain-free (NSAIDs)
PCN and cephs
PPIs
rifamPin

-also, don’t forget about infections (mycoplasma) or autoimmune disease (Sjogren’s, SLE, sarcoidosis)