Osteolytic Lesions: An Unexpected Diagnosis

This is the case of a patient who went to the emergency department with back pain and constitutional symptoms (weight loss, anorexia, nausea) lasting one month. Blood tests revealed hypercalcemia and new-onset kidney failure that prompted admission for study. Bone X-ray revealed multiple lytic lesions, and myeloma screening was negative. After a bone marrow biopsy guided by ultrasound of one lesion, it was possible to obtain the diagnosis of diffuse large B-cell lymphoma. We present this case for the diagnostic challenge and atypical presentation simulating multiple myeloma with hypercalcemia.