# A case of solitary bone plasmacytoma to multiple myeloma: a case report

## TL;DR

A patient with a rare rib tumor initially diagnosed as a benign condition later developed multiple myeloma after refusing recommended treatment.

## Contribution

This case highlights the progression from solitary bone plasmacytoma to multiple myeloma and the importance of adjuvant therapy.

## Key findings

- The initial diagnosis of fibrous/osteofibrous dysplasia was incorrect; histopathology confirmed solitary bone plasmacytoma.
- The patient's disease progressed to multiple myeloma 21 months after surgery due to refusal of adjuvant radiotherapy.
- This case emphasizes the need for accurate diagnosis and adherence to recommended treatment for solitary bone plasmacytoma.

## Abstract

Solitary bone plasmacytoma of the rib is uncommon but recognized. We report a case presenting with recurrent, predominantly nocturnal chest wall pain. Imaging revealed an expansile lesion on the left ninth rib and initially suggested fibrous/osteofibrous dysplasia. The patient underwent resection of the involved rib segment. Histopathology and immunohistochemistry confirmed solitary bone plasmacytoma. The patient declined the recommended adjuvant radiotherapy. Twenty-one months later, the disease progressed to multiple myeloma.