Primary
primitive neuroectodermal tumor (
PNET) of the bladder is an extremely rare and highly aggressive
neoplasm. We report a case of
PNET of the urinary bladder associated with increased serum
neuron-specific enolase (NSE) in the presence of relapse and
metastasis. A 66-year-old male presented to our department due to painless gross
hematuria. Computed tomographic urography (CTU) showed an intraluminal
tumor in the anterior bladder wall. Biopsy revealed a malignant small round blue cell
tumor. The patient denied
radical cystectomy, and
partial cystectomy was given together with resection of adjacent peritoneum. The patient was diagnosed with primary bladder
PNET after pathological inspection with
negative surgical margins. Additionally, he received 6 cycles of
chemotherapy using
etoposide and
cisplatin (EP) regime, and showed recurrence and
metastasis afterwards.
Disease progression was seen after transurethral resection (TUR) of
bladder tumor and
radiotherapy. Pelvic and retroperitoneal
metastasis triggered bilateral
hydronephrosis, and then
palliative treatment was given with bilateral percutaneous nephrostomy. Finally, he died 12 months after diagnosis.
PNETs are highly aggressive
tumors characterized by the expression of MIC2 and neural markers and the presence of
EWS-FLI1 translocation. We recommend histologic, immunohistochemical, and cytogenetic analysis in all patients with small round blue cell bladder
malignancy in order to rule out other small cell
malignancies.
Multimodal treatment, including surgery and
adjuvant chemotherapy must be initiated. Patients aged ≤30 years underwent complete resection of
tumor and standard
chemotherapy showed a better prognosis, while those with
metastasis, incomplete resection and inadequate response to
chemotherapy showed poor prognosis. Moreover, an elevated NSE may indicate a poor prognosis.