Signet ring cell adenocarcinoma is a rare subtype of mucinous adenocarcinoma that affects the gastrointestinal tract and the prostate. Prostatic signet ring cell carcinoma comprises 0.02% of all cases of prostate cancer and 0.4% of all signet ring cell cancers. The aim of this review was to summarize the existing literature on primary prostatic signet ring cell carcinoma by assessing patient demographics, clinical presentations, investigations, treatment methods, and survival outcomes.

A systematic review was conducted in multiple databases, including 46 articles comprising 89 individual cases of primary prostatic signet ring cell carcinoma. Data was extracted and analyzed using descriptive statistics.

The average age of patients with primary prostatic signet ring cell carcinoma was 68.5 years, and most cases were reported in Caucasian individuals. Clinical presentations varied, with lower urinary tract symptoms being the most common. Biochemical markers, such as prostate-specific antigen, were often elevated. Imaging modalities, including computed tomography and magnetic resonance imaging, were used for diagnosis, and it found that one-third had metastatic disease on diagnosis. Treatment options included radical prostatectomy, hormone therapy, radiation therapy, and chemotherapy. The prognosis for primary prostatic signet ring cell carcinoma was poor, with a 3-year survival rate of approximately 17%.

Primary prostatic SRCC is a very rare cancer of the prostate, of which very little is known. The disease most commonly presents with lower urinary tract symptoms and abnormal digital rectal examination. Biochemical markers such as PSA and PSAP can help identify prostate cancer but will not help differentiate primary prostatic SRCC. MRI is the imaging modality of choice, and suspicion should be raised of this pathology in patients with PI- RADS score of 4 or TNM staging of III or IV. Prognosis is generally poor, with an average survival of 50 months from diagnosis.