單一膀胱小細胞神經內分泌腫瘤經雷射完整腫瘤切除：案例報告及文獻回顧

游家豪¹、林雍偉^1,2

1臺北市立萬芳醫院泌尿科－委託臺北醫學大學辦理

2臺北醫學大學泌尿學科

Single small-cell neuroendocrine tumor of urinary bladder post laser en-bloc resection : A case report and literature review

Chia-Hao, You¹, Yung-Wei Lin^1,2

1 Department of Urology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.

2 Department of Urology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan

Introduction:

Neuroendocrine carcinoma of the urinary bladder (NECB) is a very aggressive and extremely rare cancer, with an annual incidence lower than 1–9/1,000,000, and often diagnosed at an advanced stage. The  current WHO/ISUP classification (2016) recognizes four distinct neuroendocrine neoplasms of urinary bladder – (i) Small cell neuroendocrine carcinoma (SmCC), (ii) large cell neuroendocrine carcinoma, (iii) well-differentiated neuroendocrine tumor, and (iv) paraganglioma. The main risk factors include smoking habits and exposure to carcinogenic materials such as industrial dyes.

Presentation of case:

We reported a case of 93-year-old male patient with underlying disease of hypertensive cardiovascular disease under medication control. He reported painless hematuria for one month and the urine cytology revealed benign non-specific finding. The following abdominal and pelvic computed tomography revealed bladder tumor over right lateral wall. He then received the operation of transurethral laser en-bloc resection of bladder tumor. The following pathology revealed small cell neuroendocrine carcinoma. After being discharged, the patient received outpatient department follow-up with improvement of hematuria.

Discussion and conclusion:

According to the present literature, the computed tomography finding of neuroendocrine carcinoma of urinary bladder would present with single bulky mass, protruding into the bladder lumen with irregular margins, a large implant base and infiltrating the organ wall. After intravenous administration of contrast, all lesions show enhancement, which in many cases is concentrated in the area of the wall. As for the MRI finding, NECB would micmic the urothelial carcinoma with T2 hyperintensity, T1 isointensity to detrusor muscle, and peripheral enhancement. Immunohistochemical stains show high positivity for chromogranin, synaptophysin, CD57 (Leu7) CD56, TTF-1, neuron-specific enolase, CAM5.2, Keratin7, and epithelial membrane antigen (EMA). Additionally, GATA3 has been found in 32 % of tumors.

The advantages of laser en-bloc resection including optimized resection with low residual tumor rates, improved specimen quality, higher detrusor muscle sampling rates, and a lower incidence of residual tumors at re-TURBT. The long-term follow-up including pelvic MRI and cystoscopy for oncological outcomes evaluation would be necessary for the patient.