# Osteolytic Lesions: An Unexpected Diagnosis

## TL;DR

A patient with back pain and kidney issues was diagnosed with a rare lymphoma after initial tests suggested multiple myeloma.

## Contribution

Highlights the diagnostic challenge of atypical lymphoma presentations mimicking multiple myeloma.

## Key findings

- The patient presented with hypercalcemia and kidney failure, typical of multiple myeloma.
- Bone marrow biopsy confirmed a diagnosis of diffuse large B-cell lymphoma instead of myeloma.
- This case emphasizes the need for thorough evaluation in atypical presentations.

## Abstract

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.