Large cell neuroendocrine carcinoma with high grade urothelial carcinoma of the kidney:a case report and review of literature

Objective:To investigate the clinicopathological features,diagnosis and differential diagnosis of renal large cell neuroendocrine carcinoma.Methods: We reported a case of large cell neuroendocrine carcinoma with high grade urothelial carcinoma of the kidney.Its clinicopathological features were studied and the literature were reviewed.Results: The patient was a elderly man,and was admitted into the hospital because of hematuria.Gross examination disclosed a mass of 6cm × 5cm × 5cm in the low part of the right kidney.The mass was firm with a grey white cut surface.The part of the mass in the renal pelvis showed a papillary appearance.Histologically,most of tumor was solid with nests or trabeculae of large-sized tumor cells.Mitoses and necrosis were easily observed.The neoplastic cells were positive for synaptophysin,chromogranin A and CD56.Ki-67 index was about 40%.The part of tumor with papillary structures showed typical histology of high grade urothelial carcinoma which were negative for neuroendocrine markers.The neoplastic cells of neuroendocrine carcinoma infiltrated into the fat tissue of the renal sinus and regional lymph node metastasis was noted.Conclusion: Primary large cell neuroendocrine carcinoma with urothelial carcinoma of the kidney is very rare.It is high aggressive and prognosis is very poor.The diagnosis depends on pathological examination and immunohistochemistry.