案例報告：具泌尿上皮癌特徵之侵犯性攝護腺癌

張哲睿¹、陳嘉宏¹、張彰琦¹、陳修聖¹

臺北市立聯合醫院忠孝院區外科部泌尿科

Aggressive prostate cancer mimicking urothelial carcinoma: a case report

Che-Jui Chang¹, Jia-Hong Chen¹, Chang-Chi Chang¹, Shiou-Sheng Chen¹

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

Introduction

Generally, morphology features under endoscopic examination can be used to distinguish prostate adenocarcinoma and urothelial carcinoma. However, an uncommon and unique type of high-grade prostatic adenocarcinoma (PAC) that mimics urothelial carcinoma (UC) might be challenging to diagnose. Here, we presented a case of aggressive prostate cancer mimicking urothelial carcinoma.

Case presentation

A 55-year-old man presented with recurrent acute urinary retention at our emergency department for 2 months. In the latest registration to our emergency department, gross hematuria and dysuria was complained of. Past medical history included hypertension, type II diabetes mellitus, and benign prostate enlargement under medication control. No operation history was mentioned. He has no fever, no abdominal pain, no flank pain, no bloody stool, no tenesmus. Digital rectal examination showed smooth, firm consistency, and no hard nodule in the prostatic lobe. The prostate-specific antigen (PSA) was 26.3 ng/ml. Transrectal ultrasound demonstrated intact prostatic capsule, homogenous echogenic appearance and intravesical prostatic protrusion, and overall volume was 43.75 ml. Abdomen computed tomography reported enlarged prostate with calcifications and diffuse wall thickening of urinary bladder. Hence, cystoscope was scheduled for further evaluation and revealed papillary, thin, finger-like projections mass lesiom extending from the bladder neck past the external urethral sphincter. In the concern of urinary continence, other than the external urethral sphincter region, tumor was resected as complete as possible. Histological examination showed PAC, Gleason grade 5+5=10, involving 95% of the specimen. The immunohistochemical (IHC) studies of the tumor cells showed AMACR (+), CK7 (+), CK20 (-) and GATA3 (-). No 34BE12-positive cells were within the neoplastic groups. The features were consistent with that of PAC. Magnetic Resonance Imaging of prostate revealed ill-defined T2 low signal intensity areas were noted in bilateral prostate gland from base to apex with low Apparent diffusion coefficient value (Fig. 2). Extracapsular invasion was noted at right prostate apex. No definite enlarged lymphadenopathy could be identified in bilateral pelvic side walls and retroperitoneum of lower abdomen. Whole body bone scan revealed no definite evidence of bony metastasis. Under the impression of prostatic adenocarcinoma, cT4N0M0, STAGE IIIC, Androgen deprivation therapy with goserelin and radiotherapy with the prostate (78 Gy/39 Fr), seminal vesicles (64 Gy/32 Fr), and pelvic lymphatics (45 Gy/25 Fr) were performed.

Conclusion

We reported a case of high-grade prostate cancer found incidentally, mimicking urothelial cancer under endoscopic examination. High-grade PAC that mimics UC might be challenging to diagnose. Present illness, digital rectal examination, and PSA are crucial for differential diagnosis. The IHC study is the best tool for differentiating PAC from UC.