膀胱類澱粉沉積症病例報告：罕見的癌症模仿者

王惟弘、謝德生

國泰綜合醫院 外科部 泌尿科

A Comprehensive Case Report on Urinary Bladder Amyloidosis: A Rare Mimic of Cancer

Wei-Hung Wang, Teh-Sheng Hsieh

Division of Urology, Department of Surgery, Cathay General Hospital, Taipei, Taiwan

Abstract

In this case report, we present the case of a 49-year-old woman with no major systemic diseases who has been smoking cigarettes for the past 10 years. She initially presented to our outpatient department (OPD) with a two-month history of painless hematuria. Urinalysis indicated microscopic hematuria without proteinuria. Further investigation through intravenous pyelography (IVP) revealed a thickened bladder wall and suspicious nodular filling defects in the lower right wall of the urinary bladder. Subsequent cystoscopy identified a bladder tumor on the right lateral wall near the dome. Transitional cell carcinoma (TCC) of the bladder was suspected. Consequently, a transurethral resection of the bladder tumor (TURBT) was performed, followed by intravesical instillations of mitomycin C post-surgery. Microscopically, the pathologist confirmed the absence of carcinoma but observed the presence of pinkish material deposition within the lamina propria and muscularis propria. Under polarized microscopy and after Congo red staining, this deposit exhibited apple-green birefringence, confirming the diagnosis of bladder amyloidosis. Following treatment, her hematuria resolved, and she is scheduled for follow-up at our OPD.

Amyloidosis encompasses a group of conditions marked by the abnormal deposition of amyloid proteins in various organs and tissues. Amyloidosis can manifest as either a systemic, typically progressive and often fatal condition, or a localized variant. Localized amyloidosis of the urinary bladder is rare, with only around 200 cases reported globally. The clinical significance of bladder amyloidosis lies in its clinical resemblance to bladder cancer, both in terms of presentation and cystoscopy appearance. The hallmark diagnostic feature is the presence of amyloid, which is confirmed through polarized microscopy after Congo red staining. The standard treatment for this condition involves transurethral resection of the lesion. However, due to a relatively high recurrence rate of approximately 50%, long-term follow-up with annual cystoscopy is recommended. In this report, we present this case to share our experience of the diagnosis and management of this peculiar disease. It emphasizes the significance of an accurate diagnosis of localized bladder amyloidosis in guiding effective patient management and improving outcomes. Continued research and awareness of this condition are crucial to ensure an accurate diagnosis and appropriate care.