Hypercalcemia of malignancy is often secondary to which underlying process?

Hypercalcemia of malignancy is often secondary to which underlying process?

• A. Pneumonia
• B. Liver metastasis
• C. Bony metastasis
• D. Renal failure

Answer: (C)

Hypercalcemia of malignancy most often results from osteolytic activity driven by tumor involvement of bone. When cancer cells metastasize to bone, they and surrounding cells release cytokines and mediators that stimulate osteoclasts, leading to increased bone resorption. As bone is broken down, calcium is released into the bloodstream, raising serum calcium levels. This mechanism explains why cancers that seed the bone frequently cause hypercalcemia. While humoral factors like PTH-related peptide can cause high calcium without bone lesions in some cancers, the classic and most common driver when metastasis to bone is present is the osteolytic destruction of bone. Pneumonia or liver metastases don’t produce this direct osteolytic effect, and renal failure raises calcium primarily through decreased excretion rather than the tumor-driven bone resorption pathway.

Hypercalcemia of malignancy most often results from osteolytic activity driven by tumor involvement of bone. When cancer cells metastasize to bone, they and surrounding cells release cytokines and mediators that stimulate osteoclasts, leading to increased bone resorption. As bone is broken down, calcium is released into the bloodstream, raising serum calcium levels. This mechanism explains why cancers that seed the bone frequently cause hypercalcemia. While humoral factors like PTH-related peptide can cause high calcium without bone lesions in some cancers, the classic and most common driver when metastasis to bone is present is the osteolytic destruction of bone. Pneumonia or liver metastases don’t produce this direct osteolytic effect, and renal failure raises calcium primarily through decreased excretion rather than the tumor-driven bone resorption pathway.