Challenges in managing extensive brown tumors and renal stones in a young man with parathyroid carcinoma and single kidney: Case report oleh Syeda Sara Tajammul, Syed Furqan Hashmi, Zamzam Al Hashami, Laila Al Masaoudi, Sharjeel Usmani, Asma Naz Nadaf, Layth Mula-Hussain