Basal Cell Carcinoma of the Prostate Misdiagnosed as High-Grade Urothelial Cancer - A Case Report of a Diagnostic Pitfall

Abstract

Purpose: Basal cell carcinoma of the prostate is rare. Usually, it is diagnosed in elderly men with nocturia, urgency, lower urinary tract obstruction and normal PSA.

Case presentation: We report on a case of a 56-years-old patient who presented at the emergency ward with weight loss, nausea and vomiting. The diagnostic evaluation showed acute renal failure due to a bladder tumor. After admission to the urology ward and subsequent contrast-enhanced CT urography and contrast-enhanced chest CT, a non-metastatic bladder tumor that infiltrated the right side of the bladder and seminal vesicles was found. High-grade muscle-invasive urothelial carcinoma was diagnosed from TURBT specimens, followed by radical cystoprostatectomy with pelvic lymphadenectomy and formation of ureterocutaneostomy sec. Bricker. The histopathological examination of the resection specimen surprisingly revealed the presence of prostatic basal cell carcinoma pT4N0M0 and not urothelial cancer. Due to renal failure, the patient required hemodialysis. The recommendation of the multidisciplinary oncological meeting was to follow up with the patient by the surgeon-urologist. On imaging six months after surgery, it was suspicious for recurrence. Patient was considered for adjuvant oncological treatment.

Conclusion: Although rare, basal cell carcinoma of the prostate should be considered in patients with lower urinary tract symptoms, hematuria and normal PSA. Transurethral resection of bladder tumor is indicated in patients presenting with hematuria and bladder tumor. In evaluation of such cases rare histological types should be included in the differential diagnosis.

Keywords: basal cell carcinoma of the prostate; bladder tumor; cystoprostatectomy; prostate cancer; renal failure; transurethral resection of bladder tumor.

Figure 1

Contrast-enhanced CT urography, coronal (A) and sagittal (L) view of the tumor (encircled with the red line). Left side (A) is showing the tumor extending into the urinary bladder. On the right side (L) the tumor extends into the urinary bladder, prostate and seminal vesicles.

Figure 2

Poorly differentiated tumor with invasion of muscularis propria is present in TURBT specimen (asterisk). (A) Extensive cautery artifacts made histologic evaluation difficult (HE stain). (B) Strong positive nuclear reaction to GATA3 in bladder tumor, falsely indicating the tumor to be of urothelial origin.

Figure 3

Morphology of the tumor in the cystoprostatectomy specimen. (A) Tumor cells in luminal portions of the bladder are growing in small irregular nests (arrow) and as single cells. No urothelial carcinoma in situ was detected (asterisk) (HE stain). (B) Tumor cells in deeper portions of bladder are growing in solid nests and cords with presence of eosinophilic basement membrane-like material and focal microcystic architectural pattern, indicative of basal cell carcinoma (asterisk) (HE stain). (C) Periurethral portion of the prostate infiltrated with basal cell carcinoma growing in cords and as single cells with intratumoral hemorrhage (asterisk) (HE stain). (D) GATA3 stain of periurethral portion of prostate is showing positive tumor cells (asterisk) as well as basal cells of normal prostate glands and urothelium of prostatic urethra (arrows).