Background
Primary seminoma of the prostate (PSP) is a rare type of extragonadal germ cell tumour that is easily misdiagnosed, owing to the lack of specific clinical features. It is therefore necessary for clinicians to work toward improving the accuracy of PSP diagnosis. Case summary: A 59-year-old male patient presenting with acute urinary retention was admitted to a local hospital. A misdiagnosis of benign prostatic hyperplasia led to an improper prostatectomy. Histopathology revealed PSP invading the bladder neck and bilateral seminal vesicles. Further radiotherapy treatment for the local lesion was performed, and the patient had a disease-free survival period of 96 mo. This case was analysed along with 13 other cases of PSP identified from the literature. Only four of the cases (28.6%) were initially confirmed by prostate biopsy. In these cases, imaging examinations showed an enlarged prostate (range 6-11 cm) involving the bladder neck (13/14). Of the 14 total cases, 11 (78.6%) presented typical pure seminoma cell features, staining strongly positive for placental alkaline phosphatase, CD117, and OCT4. The median age at diagnosis was 51 (range 27-59) years, and patients had a median progression-free survival time of 48 (range 6-156) mo after treatment by cisplatin-based chemotherapy combined with surgery or radiotherapy. The remaining three were cases of mixed embryonal tumours with focal seminoma, which had clinical features similar to those of pure PSP, in addition that they also had elevated serum alpha-fetoprotein, beta-human chorionic gonadotropin, and lactose dehydrogenase.
Conclusion
PSP should be considered in patients younger than 60 years with an enlarged prostate invading the bladder neck. Further prostate biopsies may aid in proper PSP diagnosis. Cisplatin-based chemotherapy is still the main primary therapy for PSP.