# Bisphosphonate-Induced Orbital Cellulitis in a Patient With Suspected Parathyroid Carcinoma: A Case Report

## TL;DR

A 79-year-old man developed rare orbital inflammation after bisphosphonate treatment, which was successfully treated, and the challenges of diagnosing parathyroid carcinoma are discussed.

## Contribution

This case report highlights the rare side effect of bisphosphonate-induced orbital cellulitis and the diagnostic challenges of parathyroid carcinoma.

## Key findings

- Orbital cellulitis occurred following intravenous pamidronate disodium treatment in a patient with severe hypercalcaemia.
- The patient's condition was successfully managed, emphasizing the importance of recognizing this rare side effect.
- The case underscores the difficulties in diagnosing parathyroid carcinoma.

## Abstract

Bisphosphonates are widely used for a number of metabolic bone conditions. Orbital inflammation is a very rare side effect of bisphosphonate therapy that can risk permanent visual loss. We describe the complex case and successful treatment of a 79-year-old man who developed orbital cellulitis following the use of intravenous pamidronate disodium for severe hypercalcaemia. The challenges regarding the diagnosis of parathyroid carcinoma are also discussed.