AB155. Primary large cell neuroendocrine carcinoma of ureter: a case report and review of the literature

Objective: Large cell neriendocrine carcinoma (LCNEC) is an extremely rare malignant tumor in the ureter. To investigate the etiology, clinical manifestation, diagnosis and treatment of LCNEC.

Methods: We report a case of a 74-year-old woman who complained of right lower back pain and discomfort with intermittent hematuria was admitted to our hospital in 2012. Urinary ultrasound showed right kidney hydronephrosis and left ureteral expansion. The patient did not present clinical symptoms, neither frequent micturition, micturition pain, nor urinary urgency. The blood routine and biochemical parameters were within normal range, except for an elevated serum creatinine level of 156 umol/L and serum urea level of 11.2 mmol/L. Voiding urethrocystography was performed three times, but the results were negative. As the patient with poor renal function and did not undergo the enhanced computed tomography (CT). CT non-contrast enhanced scan revealed atrophy of the left kidney, right hydronephrosis and a space-occupying lesion (20 mm × 16 mm) in the right lower ureter that was preliminarily considered a ureteral tumor. Emission CT of the kidney showed impaired renal function, as evidenced by a marked decrease in the glomerular filtration rate of the left kidney (7.2 mL/min) and a compensatory increase in the glomerular filtration rate of the right kidney (71.3 mL/min). Flexible ureteroscopes were performed in the patient for further examination, which revealed the ureter clogged by a long strips and gray color stiff mass, with the scope inserted 6 cm to the right ureterostoma. The surface of mass biopsy showed change like urothelial carcinoma. Nephroureterectomy should be perform based on the biopsy result, but considering the patient had single kidney and poor renal function, then the affected ureteric segment was excised, and the ureters were repaired by end-to-end anastomosis with a double-J tube for internal drainage. During the operation, the lesion, approximately 3 cm × 1 cm, was found in the ureter about 4 cm away from the bladder, the ureteric segment was excised 1 cm from the tumor and had pathological examination.

Results: Postoperative pathological examination with hematoxylin-eosin and immunohistochemical staining (positive expression for synaptophysin, chromogranin A and CD56, Ki 67 70%) indicated LCNEC, and the two cut edges of the ureter were free of tumor. The patient refused either adjuvant chemotherapy or radiotherapy and alive without evidence of tumor recurrence or metastasis for 25 months after surgery.

Conclusions: LCNEC is a rare and high aggressive tumor. Pathological examination and immunohistochemical staining are the most important diagnostic procedures. Due to the rarity of ureteral LCNEC, there are no standard treatment options, early surgical treatment may contribute to the prognosis.

Keywords: Neuroendocrine; carcinoma; ureter