Mucinous adenocarcinoma of the prostate: case report and review of the literature

Background: Mucinous adenocarcinoma of the prostate (MACP) is a rare variant of prostatic carcinoma that is characterized by pools of extra-acinar mucin. Precise diagnosis is important due to nonspecific findings on imaging tests, its aggressive behaviour and poor response to radiotherapy. The essential point in the diagnosis of MACP is to rule out the extraprostatic malignancies, originating from the bladder or colorectum. Case Report: A 57-year-old man presented in our clinic with urinary frequency, nocturia and voiding difficulties. Digital rectal examination revealed a slightly enlarged prostate, without palpable nodules. Patient PSA was 18.0 ng/mL. Twelve-core transrectal ultrasound-guided biopsy confirmed prostate cancer with Gleason score 8 (3+4). Up to 50% of the tumor lesion consisted of neoplastic glands with isolated cells, floating in mucinous material. The metastatic work-up, including CT scan and bone scintigraphy was negative and radical retropubic prostatectomy with lymph node dissection has been performed. Periodic Acid Schiff staining confirmed the presence of mucinous prostatic adenocarcinoma. Morphological examination was negative for lymph nodes metastases. The extraprostatic extension and surgical margins were negative. Three years after surgery, patient’s serum PSA remained undetectable, without recurrence. Conclusion:  We report this case due to the rarity of primary MACP and its challenging diagnosis. Although MACP may be associated with poor outcome, its proper diagnosis and treatment significantly contribute to favorable prognosis and patient survival.