Severe hypercalcemia requiring emergency hemodialysis and multidrug therapy in a case of diffuse large B-cell lymphoma with multiple bone lesions.

BACKGROUND

Severe hypercalcemia is a rare but serious complication observed in patients with diffuse large B-cell lymphoma (DLBCL) with multiple bone lesions. Currently, no standard therapy has been established for this life-threatening condition.

CASE PRESENTATION: A 54-year-old Japanese woman with severe hypercalcemia (serum total calcium concentration of 23.0 mg/dL) was referred to our hospital. Initial management included multiple sessions of emergency hemodialysis, aggressive hydration, and administration of calcitonin. Although these interventions temporarily improved her condition, her serum calcium levels soon rebounded. The addition of bisphosphonates did not induce a prompt or sufficient reduction in serum calcium levels. Computed tomography revealed osteolytic lesions, strongly suggestive of malignancy. Given that the pathological condition was attributed to bone lesions, denosumab was administered, leading to a marked reduction in serum calcium levels and sustained control. A definitive diagnosis of DLBCL was established through bone biopsy and bone marrow aspiration. Based on these findings, severe hypercalcemia was determined to be secondary to DLBCL with multiple bone lesions. Following the initiation of chemotherapy, her serum calcium levels remained stable during follow-up.

CONCLUSIONS

Severe hypercalcemia in this case was caused by DLBCL with multiple bone lesions. Successful management was achieved through a combination of emergency hemodialysis, aggressive hydration, and a multi-drug regimen, including calcitonin, bisphosphonates, and denosumab.