Primary malignant peripheral nerve sheath tumor of prostate in a young adult: A case report

RATIONALE: Prostate sarcoma has been reported to represent 0.7% of primary prostate malignancies. Leiomyosarcoma and rhabdomyosarcoma are the most common sarcomas of the prostate. Malignant peripheral nerve sheath tumor (MPNST) of the prostate is very rare. PATIENT CONCERNS: A 22-year-old man presented with gross hematuria and voiding difficulty for 2 weeks. Magnetic resonance imaging showed a 6-cm mass in the left lobe of the prostate. DIAGNOSES: Core needle biopsy results revealed high-grade sarcoma, suggestive of poorly differentiated synovial sarcoma. The final diagnosis of laparoscopic prostatectomy was MPNST, because it did not show the presence of SYT-SSX fusion transcripts on reverse transcription polymerase chain reaction analysis. INTERVENTIONS: Adjuvant radiotherapy was planned because preoperative positron emission tomography-computed tomography (CT) did not show any metastatic lesion and the resection margin was microscopically involved. However, chest CT showed multiple lung metastases a month after prostatectomy. A chemotherapeutic regimen of doxorubicin and ifosfamide was administered. OUTCOMES: The best response to chemotherapy was partial response. After several courses of chemotherapy, he died 9 months after the surgery. LESSONS: Primary prostate sarcoma and even MPNST are extremely rare. MPNST of the prostate has seldom been reported. This report may help diagnose and manage the disease.