Published online Apr 10, 2016. doi: 10.5306/wjco.v7.i2.265
Peer-review started: September 8, 2015
First decision: October 16, 2015
Revised: October 19, 2015
Accepted: December 18, 2015
Article in press: December 21, 2015
Published online: April 10, 2016
Processing time: 218 Days and 9.7 Hours
Parathyroid hormone mediated hypercalcemia is not always exclusively primary hyperparathyroidism and rarely could be due to ectopic parathyroid hormone secretion from tumor cells. We present a case of 86-year-old female with metastatic gall bladder adenocarcinoma diagnosed eight months back who presented with generalized fatigue and poor oral intake and was found to be hypercalcemic with elevated parathyroid hormone levels. Imaging with technetium 99 m sestamibi scintigraphy with dual phase, subtraction thyroid scan (dual isotope scintigraphy), magnetic resonance imaging and ultrasonography did not demonstrate any parathyroid lesion in normal or ectopic sites. We believe that the tumor cells were the source of ectopic parathyroid hormone secretion as we had excluded all the other possibilities with extensive combined imaging thereby increasing the sensitivity of our testing. We report the first case of metastatic gall bladder adenocarcinoma with paraneoplastic ectopic parathyroid hormone secretion.
Core tip: Gallbladder carcinoma rarely can cause hypercalcemia with very few reported cases but they were all due to parathyroid hormone (PTH) related peptide. We present the first case of metastatic gallbladder adenocarcinoma with hypercalcemia due to ectopic PTH secretion from tumor cells. PTH mediated hypercalcemia is not exclusively primary hyperparathyroidism and awareness of this rare paraneoplastic presentation will prevent unnecessary parathyroid surgeries. Moreover this case prompts physicians to look for another ectopic source in the absence of parathyroid lesion which would facilitate early diagnosis of an underlying malignancy.