Multiple bone lesions and hypercalcemia presented in diffuse large B cell lymphoma: mimicking multiple myeloma?

Area of Science:

• Oncology
• Hematology
• Endocrinology

Background:

• Diffuse large B cell lymphoma (DLBCL) can present with hypercalcemia and bone lesions.
• The pathogenesis of these complications is not fully understood but may involve altered bone metabolism.

Observation:

• A 58-year-old female patient with DLBCL developed hypercalcemia and multiple osteolytic bone lesions.
• Her symptoms included pain, nausea, and vomiting.
• Radiographic examination confirmed widespread osteolytic lesions.

Findings:

• Mesenchymal stem cell osteogenic potential correlated with Dickkopf-1 (DKK-1) expression in bone marrow and lymphoma cells.
• Elevated PTH-related protein (PTHrP) was detected in lymphoma cells and serum.
• Increased receptor activator of nuclear factor kappaB ligand (RANKL) was observed in bone marrow plasma and mesenchymal stem cells.

Implications:

• These factors (DKK-1, PTHrP, RANKL) suggest dysregulation of osteoblast and osteoclast differentiation in lymphoma-associated hypercalcemia.
• The findings offer insights into the mechanisms underlying bone complications in DLBCL, similar to multiple myeloma.