Elevated PTH-Related Protein hormone - in particular squamous cell cancer, breast, ovarian, lymphoma
Direct bone erosion e.g. myeloma, breast
Inappropriate production of 1,25-OH vit dā lymphoma
Symptoms
Related to primary cancer as well as hyper ca2+ ā fatigue, confusion, pain, weakness
Can be relatively acute, varying with cancer burden
Tests
Elevated PTH-Related Protein w/squamous cell ca, ovarian, breast, bladder, lymphoma (and decreased PTH)
Direct bone erosion from breast, multiple myeloma--> PTH and PTH-Rp low, imaging w/evidence boney mets; elevated urine or serum protein electrophoresis w/multiple myeloma