A Rare Pancreatic Tumor Killed a Patient by Flooding Her Blood with a Calcium-Raising Peptide

Single-patient case report documenting clinical presentation, diagnostic workup (identifying PTHrP secretion as the cause of hypercalcemia), treatment attempts, and outcome over the disease course.

Pancreatic neuroendocrine tumors are often slow-growing and manageable, but when they secrete PTHrP, the resulting hypercalcemia can be rapidly fatal and resistant to standard treatments. This case underscores the need for early identification of PTHrP-secreting tumors so that surgical cytoreduction — the most effective treatment — can be attempted before the metabolic complications become uncontrollable.

PTHrP is one of the most clinically important tumor-secreted peptides — it's the leading cause of humoral hypercalcemia of malignancy, most commonly seen with solid tumors like lung and renal cancer. Its occurrence with pNETs is much rarer but particularly dangerous because the otherwise treatable nature of pNETs creates a false sense of security. This case adds to growing calls for routine PTHrP measurement in pNET patients presenting with hypercalcemia.

As a single case report, no generalizable treatment conclusions can be drawn. The patient was unfit for curative surgery, so the potential benefit of cytoreduction couldn't be assessed. Alternative therapies (cinacalcet, newer anti-PTHrP approaches) were not discussed.