So, in researching this further, I figured out a way to rule the other answeres out. Per this article, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4683803/, humoral hypercalcemia of malignancy is caused by 4 mechanisms with excess PTHrP secretion being MCC. Excess PTHrP secretion occurs in "squamous cell cancers, urinary tract cancers (renal cancer and bladder cancer), breast cancer, nonHodgkin's lymphoma, and ovarian cancer account for the majority of malignancies leading to hypercalcemia via PTHrP." The other 3 causes include hypercalcemia secondary to overproduction of cacitriol, osteolytic metastases, and PTH mediated hypercalcemia (parathyroid carcinoma and ectopic production). Also, FA only mentions PTHrP in regards to SCC of lung and renal cell carcinoma.
Prostate, colon, and pancreatic cancers are more commonly adenocarcinoma, and less likely to release PTHrP, and thyroid cancer is also less likely, though I did find one article that found PTHrP released by all of these cancers so I don't know. I guess I'm just going to go with SCC of lung being MCC of PTHrP humoral hypercalcemia of malignancy, plus patient's demographics (60's male).
I understand why it's lung now, but I picked thyroid gland because often times thyroid tumors press on the parathyroid sitting above, which causes the parathyroids to secrete more Ca...can someone comment if they've read this too?
fa 2020 pg 332 you can see a parenthesis saying sq. cell ca of lung can act as PTHrP LIKE PTH
Why can this not be MEN 1? And the increased serum calcium be a result of increased PTH release from parathyroid?
submitted by bigbootycorgi(5)
I thought of this as squamous cell carcinoma of the lung causing increased PTHrP and hypercalcemia.