Bilateral Hydronephrosis Secondary to Giant Cell Tumor of the Sacrum.

Sacral giant cell tumors (GCTs) are rare entities that exhibit slow progressive growth and become clinically apparent when they reach a considerable size. The current case report discusses the presentation, investigation, and management of a young male patient diagnosed with a large sacral mass. A 17-year-old male patient presented with uremia, bilateral lumbar pain, and severe weakness of his lower extremities. Imaging revealed a midline sacral mass causing bilateral upper tract obstruction. The patient underwent bilateral nephrostomies followed by a partial en bloc sacrectomy and curettage of the tumor bulk. Histopathology revealed a giant cell tumor of the sacrum. Postoperatively, the patient received adjuvant radiotherapy and rehabilitation for his neurological symptoms. Sacral GCTs are essentially benign but behave like a malignant tumor in view of frequent recurrences and reports of malignant transformation. Surgery with wide local excision remains the ideal modality for complete clearance of sacral tumors. Nevertheless, limitations include their large size, difficult operative access, risk of fatal intraoperative bleeding, and inevitable high postoperative morbidity.