Primitive neuroectodermal tumor of the prostate in a 58-year-old man: A case report

BACKGROUND Primitive neuroectodermal tumor (PNET), especially located in the prostate, is a rare tumor that mainly occurs in young men. Bladder or rectum invasion and distant metastasis are strongly associated with a poor prognosis. Combination therapy, including radical surgery, adjuvant chemotherapy, and radiotherapy, is available. We present a case of prostatic PNET and a review of 17 cases identified in the literature. CASE SUMMARY A 58-year-old man was admitted complaining of dysuria for 2 years. Computed tomography and magnetic resonance imaging showed a large cystic-solid mass in the pelvic cavity compressing the surrounding bladder and rectum. The mass was iso- to hyperintense on T1-weighted imaging (WI) and heterogeneously hyperintense on T2WI. Cystic degeneration and necrosis were seen in the tumor, and solid tissues within the mass enhanced on contrast-enhanced scan. The patient underwent robot-assisted laparoscopic pelvic tumor resection. Histologically, the presence of many small round cells that were positive for expression of CD99, vimentin, and synaptophysin established the diagnosis of PNET in the prostate after surgery. The patient underwent adjuvant chemotherapy. During 34 mo of follow-up, the patient had no signs or symptoms of recurrence or residual disease. CONCLUSION We present the case of the oldest prostatic PNET patient, who has a good prognosis. This illustrates how older men with prostatic PNET may also benefit from the combination therapy, like younger adults, and achieve a long-term survival. As always, PNET should be considered in the differential diagnosis of aggressive prostatic tumors in young men.