Urothelial Carcinoma With Bone Metastasis Mimicking Sciatica: A Common Neoplasm With an Uncommon Presentation.

Bone metastasis in urothelial cancer is underreported and not well-researched. A case of urothelial carcinoma (UC) with bone metastasis presenting as musculoskeletal pain is reported. The patient presented with persistent lower back pain associated with right lower extremity pain, numbness, and tingling. Initially, a diagnosis of sciatica was suspected, but the patient did not respond to treatment. An MRI spine was done, which revealed a bright signal mass in the vertebral body suspicious for a metastatic lesion, left hydroureteronephrosis, and a nonspecific cystic focus in the right iliacus muscle. Subsequent imaging revealed an irregular soft tissue mass at the left posterolateral bladder base, resulting in apparent obstruction of the left ureter, highly suggestive of neoplasm, along with numerous lytic bone lesions in the pelvic girdle with associated soft tissue masses, consistent with metastatic disease. The patient underwent an interventional radiology biopsy of the right iliac soft tissue mass to evaluate the lytic bony lesions, which revealed metastatic carcinoma, consistent with UC. A prompt referral was made for urology and oncology consultations. The patient underwent left percutaneous nephrostomy placement for obstruction, but he was not a candidate for any systemic therapy because of his poor performance status, and hospice was recommended as his metastatic disease was not curable and the goal of any kind of treatment was palliative. The optimal treatment for UC with bone metastasis remains divergent, and the management options should be determined as part of a shared decision-making process. This case highlights the importance of having a high suspicion of neoplastic pathology in patients presenting with musculoskeletal pain, like back pain, and not responding to treatment. This should alert the physicians to the potential for serious disease processes.