Abstract / Summary
Abstract Background Primary leiomyosarcoma (LMS) of the urinary bladder is a rare non-urothelial malignancy, comprising well under 1% of bladder tumors, with fewer than 200 cases reported worldwide. Reported series place the median age of onset between the fifth and sixth decades (49–65 years). 1–4 A reproductive-age presentation with a synchronous, radiologically indeterminate uterine enlargement — as in this case — has only one closely comparable precedent in the literature. Case Presentation: A 43-year-old Indian woman with type 2 diabetes presented with hematuria, dysuria, abdominal pain, vomiting, and fever following TURBT for a bladder mass elsewhere. Cross-sectional imaging showed a heterogeneously enhancing polypoidal bladder mass (5.5 × 8 × 4.2 cm) directly abutting a bulky uterus, raising concern for a synchronous gynecologic process. TURBT histology showed a malignant spindle cell neoplasm. She underwent single-stage radical cystectomy with urethrectomy, bilateral pelvic lymphadenectomy, hysterectomy with bilateral salpingo-oophorectomy, and ileal conduit diversion. Final histopathology confirmed a unifocal FNCLCC Grade 3 leiomyosarcoma (6.4 × 5.2 × 7 cm) with clear margins and 0/28 nodes involved (pT1N0) — a favorable stage atypical for a grade 3, size-discordant sarcoma. Immunohistochemistry was positive for desmin, SMA, and vimentin, and negative for pan-cytokeratin, S100, SOX10, myogenin, and MyoD1, excluding carcinoma, melanoma/nerve sheath tumor, and rhabdomyosarcoma. The uterus, tubes, and ovaries were histologically benign. Patient is currently on adjuvant chemotherapy and regular follow up. Conclusion This case is notable for three co-occurring features: an age below the typical reporting median, a synchronous bulky uterus that mimicked a gynecologic primary and was managed with prospectively planned combined urologic–gynecologic surgery to a favorable outcome, and a grade–stage discordance. We also summarize the clinical and radiological features separating bladder leiomyosarcoma from urothelial carcinoma, rhabdomyosarcoma, and leiomyoma.