Cystic epithelial-stromal tumors of the prostate are rare, with 82 cases reported in literature. These cases have been published under a variety of diagnoses, including phyllodes tumor and prostatic stromal proliferation of uncertain malignant potential as well as a malignant tumor called “prostatic stromal sarcoma”. We report a case of a 60-year-old man with the histological diagnosis of phyllodes tumor of the prostate in transurethral resection specimen.
Prostatic cystic epithelial-stromal tumors, commonly described as phyllodes tumors of the prostate, are extremely rare lesions. They exhibit a spectrum of histological features similar to their better-known counterpart in the breast. Although a benign clinical course has been emphasized in some reports, cumulative evidence in literature indicates that these lesions should be considered neoplasms rather than atypical hyperplasia due to the frequent early recurrences with possible dedifferentiation, infiltrative growth, and potential for extraprostatic spread in some cases. An individualized approach to complete excision of the tumor is needed. A case report of a patient recently treated in our hospital is presented, and a review of literature was done.
A 60-year-old man, who visited our hospital, complained of dysuria and bladder outlet obstruction. Digital rectal examination revealed a slightly enlarged benign-feeling prostate. Prostate-specific antigen was 1.1 ng/mL. The urine culture showed no urinary tract infection. X-ray of the kidneys, ureters, and bladder was normal, as was renal ultrasound. Transrectal ultrasound revealed an increased prostate volume (60 mL) without suspicious hypodense or hyperdense areas. Cystoscopy demonstrated enlarged prostate adenoma causing bladder outlet obstruction, which was subsequently resected.
Pathological examination showed a benign prostatic hyperplasia and features of complex glandular architecture with a prominent stromal component (Figure
Phyllodes tumor of the prostate, with leaflike protrusions into a cystic cavity and broad stromal compound (Goldner
Phyllodes tumor of the prostate: proliferations of elongated and spindle-shaped cells within the stroma and benign glandular elements (H & E
Additional staging investigations including X-ray of the lung and abdominal magnetic resonance imaging revealed no extracapsular extension of the tumor with absence of lymph node involvement or metastasis. Sextant biopsies of the peripheral zone demonstrated normal prostatic tissue. The patient denied radical surgery, and we performed a second transurethral resection of the prostate three months later without further recurrence of the phyllodes tumor. Due to the malignant potential and the possibility of sarcomatoid differentiation of this tumor entity, we perform periodical close followup every three months in order to be able to detect and to treat any progression at an early stage by radical surgical intervention. The patient remains alive and well without recurrence of the phyllodes tumor after 18 months.
Phyllodes tumor of the prostate is an uncommon prostatic neoplasm with distinctive clinical and pathological characteristics. It has been assigned numerous names during the last 20 years, including prostatic cystic epithelial-stromal tumor, phyllodes type of atypical hyperplasia, cystadenoleiomyofibroma, prostatic stromal proliferation of uncertain malignant potential, and cystosarcoma phyllodes [
Although the mean age of patients who present with phyllodes tumors is about 55 years, age range at presentation from 22 to 86 years and 40% of the patients are younger than 50 years [
Histologically, phyllodes tumor of the prostate is biphasic, consisting of stromal and epithelial components arranged to form cysts lined by hyperplastic epithelium. The proliferating stroma is of variable cellularity and sometimes shows subepithelial condensation. The lining epithelium is benign, with basal cell and secretory layers that show immunoreactivity typical of prostatic epithelium, but may show various metaplastic and proliferative changes such as basal cell hyperplasia or squamous metaplasia [
Tumor recurrence after transurethral resection is common, occurring in 65% of patients overall, with recurrence rates from 50% for low-grade tumors to 100% for high-grade tumors [
Since phyllodes tumor is potentially aggressive, complete tumor resection propably provides the best chance for cure. In low-grade tumors alternatively, as in our case, close cystoscopic and transrectal ultrasound surveillance after 2nd transurethral resection without further detectable tumor can achieve local control. However, careful surveillance is essential as progression to higher grades can occur, requiring more aggressive intervention.