三角區侵犯之高惡度膀胱癌合併癌肉瘤：恥骨上疼痛為初始表現的非典型病例

孫浩議¹、陳嘉宏¹、張彰琦^1,2、邱逸淳^2,3

¹臺北市立聯合醫院忠孝院區外科部泌尿科

²國立陽明交通大學醫學院

³臺北市立聯合醫院陽明院區外科部泌尿科

High-Grade Urothelial Carcinoma With Carcinosarcoma Component Presenting as Progressive Suprapubic Discomfort in an Elderly Male

Hao-Yi Sun ¹, Chia-Hung Chen ¹, Chang-Chi Chang ^1,2, Yi-Chun Chiu ^2,3

¹ Division of Urology, Department of Surgery, Zhongxiao Branch, Taipei City Hospital

² National Yang Ming Chiao Tung University, School of Medicine, Taipei, Taiwan

³ Division of Urology, Department of Surgery, Yangming Branch, Taipei City Hospital

Introduction:

Bladder cancer most commonly presents with painless hematuria, yet a proportion of patients manifest atypical symptoms, particularly when the tumor arises from or extensively involves the trigone and posterior bladder wall. Deep submucosal infiltration, local inflammatory reaction, and obstruction of the ureterovesical junction can generate referred discomfort perceived as suprapubic pain rather than typical urinary symptoms. Carcinosarcoma of the bladder, a rare biphasic neoplasm containing both epithelial and mesenchymal elements, is associated with rapid local expansion and substantial mass effect at presentation ^1-3. We report an elderly man who developed progressively worsening suprapubic discomfort and anemia without hematuria, ultimately found to have high-grade urothelial carcinoma with carcinosarcoma differentiation causing extensive trigonal involvement and bilateral obstruction.

Case presentation:

The seventy-seven-year-old male high-school teacher, a nonsmoker without alcohol use, developed persistent lower abdominal pain beginning four months after left inguinal hernioplasty. The discomfort gradually intensified and was accompanied by a decline in hemoglobin from twelve to nine grams per deciliter, without fever, gross hematuria, weight loss, or wound abnormalities. Computed tomography demonstrated an irregularly enlarged prostate, pelvic peritoneal thickening with surrounding fat stranding, and bilateral hydronephrosis, yet no clear explanation for the obstruction (Fig. 1). Cystoscopic evaluation revealed multiple papillary lesions carpeting the trigone, raising concern for an underlying malignant process (Fig. 2). During transurethral resection, the bladder was found to harbor a large, friable, and extensively infiltrative tumor involving the trigone, posterior wall, and both lateral walls, with complete obscuration of the ureteral orifices. Bilateral nephrostomy tubes were inserted with subsequent ureteral stent placement. The postoperative course was smooth; nephrostomy tubes were removed on postoperative day four, and he was discharged on postoperative day six with adequate bladder emptying and stable renal drainage.

Histopathologic examination showed high-grade invasive urothelial carcinoma with focal squamous differentiation in the initial specimen. A separate specimen demonstrated a carcinosarcoma component composed of malignant epithelial nests admixed with spindle-cell sarcomatous elements in an inflamed stromal background. Muscularis propria was not present in the submitted tissue, limiting precise pathological staging. The combined morphologic findings corresponded to the extensive, rapidly progressive tumor observed endoscopically and accounted for the degree of bilateral upper urinary tract obstruction seen at presentation.

Conclusion:

An elderly male who presented with progressive suprapubic discomfort and anemia without hematuria was found to have high-grade urothelial carcinoma with a carcinosarcoma component, extensively invading the trigone and causing bilateral upper tract obstruction. The tumor’s location and mass effect account for the atypical pain-dominant presentation. Clinicians should consider bladder malignancy in older patients with persistent suprapubic discomfort accompanied by unexplained hydronephrosis or anemia, even in the absence of urinary symptoms.

Discussion:

This case demonstrates how bladder tumors with prominent trigonal and posterior wall involvement may present predominantly as progressive suprapubic discomfort. The tumor’s broad contact with the bladder base, coupled with inflammatory stromal reaction and increased intravesical pressure from obstructed ureteral orifices, can stimulate pelvic visceral afferents, producing dull suprapubic pain rather than hematuria. The concurrent decline in hemoglobin likely reflected chronic oozing from the friable tumor surface rather than gross bleeding, further blurring the clinical picture. Imaging revealed bilateral hydronephrosis and pelvic fat stranding, findings that are compatible with a deeply infiltrative bladder process but may initially be nonspecific ⁴. Cystoscopy clarified the source, showing a large friable mass extensively involving the trigone and lateral walls with complete loss of ureteral orifice visibility. This pattern is characteristic of rapidly expanding high-grade disease capable of causing silent yet progressive upper tract obstruction. Histopathology confirmed high-grade invasive urothelial carcinoma with focal squamous differentiation as well as a separate carcinosarcoma component. The latter is known for rapid proliferation, stromal invasion, and a tendency toward bulky presentation, correlating with the extensive tumor burden seen intraoperatively ^1,5. The absence of muscularis propria in the resected tissue limited definitive staging, yet the combination of bilateral obstruction, trigonal encasement, and aggressive histology strongly suggested advanced local disease.