High-grade spindle cell sarcomas are rare undifferentiated pleomorphic cancers that present a treatment challenge to urological practices, especially when they present in the pelvis. We report a 46-year-old male patient who presented to our urology clinic with urinary retention after having a Foley catheter placed at an outlying facility. A voiding trial was attempted, but the patient failed this trial. This failure resulted in cystoscopy with bilateral retrograde pyelograms, which revealed a compressed bladder due to extrinsic compression. This finding had been evaluated with a computed tomography (CT) scan with and without intravenous contrast that showed a 14 cm pelvic mass with bladder displacement and compression. A fine needle aspiration was done at this outlying facility, prior to referral to our office, and it confirmed spindle cell pathology. The mass was surgically excised with the histology revealing a pelvic spindle cell sarcoma with positive surgical margins. Further, metastatic work-up with CT/positron emission tomography revealed bone and lung metastasis. The patient is currently undergoing chemotherapy and radiation. In this case study, we will review staging, management, differential diagnosis, chemotherapy, and radiation.