2 Dec - Hypercalcemia

This AMs case was a 62 y/o female who presented with progressive muscle weakness of several weeks duration.  There was also some complaints of numbness.  She had lost a significant amount of weight and was not eating well due to some abdominal pain.  She was brought to the hospital when she was no longer able to stand.  Her past history was remarkable for MS, but this was significantly different from any of her prior flares.  She did report a 40 pack year history of smoking.

On initial lab evaluation she was found to have an elevated calcium at ~ 17.  Phosphorus was elevated as well.  Her PTH was 20, and PTHrP is pending at this time.  Her CXR revealed a large perihilar lung mass and follow up CT of the chest revealed the mass and assocaited mediastinal adenopathy.

She recieved IV fluids, furosemide, dexamethasone, calcitonin, and pamidronate.  Her muscle weakness improved as her calcium levels fell.

Hypercalcemia is one of the most common oncologic emergencies.  It is either humoral in origin from ectopic PTHrP secretion by the tumor, due to overexpression of 1,25 vit D by lymphomas, or due to direct bony destruction such as in myeloma.  It usually occurs in patients with known cancer but can be a presenting symptom of the disease.  Patients are often quite volume depleted and require significant amounts of IV fluids in the first few hours.  If calcitonin is given, it must be IM or IV, as the intranasal formulation is not active. 

This article from Mayo Clinic Proceedings summarizes hypercalcemia and other common oncologic emergencies and should be reviewed.

Contrast this presentation with an earlier discussion of hyperparathyroidism.  Remember that in general calcium levels over 12 are almost always due to malignancy.