Large Cell Neuroendocrine Carcinoma of the Colon With Carcinomatosis Peritonei.

Colorectal large-cell neuroendocrine carcinomas (NECs) are extremely rare and have very poor prognosis compared to adenocarcinomas. A 74-year-old man presented with abdominal pain, diarrhea and hematochezia. The histopathologic report of colonoscopic biopsy performed at a local clinic was a poorly differentiated carcinoma. An abdominopelvic computed scan revealed irregularly enhanced wall thickening at the sigmoid colon with regional fat stranding and lymphnode enlargement. He underwent a laparoscopic high anterior resection with selective peritonectomy for peritoneal carcinomatosis, intraoperative peritoneal irrigation chemotherapy, and early postoperative intraperitoneal chemotherapy for 5 days. The tumor had a high proliferation rate (mitotic count > 50/10 HPFs and 90% of the Ki-67 index) and lymph-node metastases had occurred. On immunohistochemistry, the tumor cells expressed CD56 and synaptophysin. Large-cell NEC was confirmed. Systemic chemotherapy with cisplatin/etoposide was done. The patient is still alive after 3 years with no evidence of recurrence.

Clinicopathologic significance of gastric adenocarcinoma with neuroendocrine features.

PURPOSE: Composite neuroendocrine-exocrine carcinomas are malignancies that have two distinct components residing within the same tumor: an adenocarcinomatous portion and a neuroendocrine portion. This is rare in gastric cancers; however, poorly differentiated adenocarcinomas can sometimes reveal evidence of neuroendocrine features (NEF) or be 'mixed endocrine and exocrine carcinomas'. This study aimed to review NEF in gastric adenocarcinoma and to evaluate its prognostic significance. MATERIALS AND METHODS: We selected 29 patients who were diagnosed with gastric adenocarcinoma with NEF and received gastrectomies at the Department of Surgery, Ajou University Hospital between January 2001 and December 2009. We analyzed the clinicopathologic features of gastric cancer with NEF and the prognosis associated with such tumors. RESULTS: THE PATHOLOGIC RESULT WITH RESPECT TO TNM STAGING OF THE GASTRIC CANCERS WITH NEF WERE AS FOLLOWS: 5 cases of T1, 5 cases of T2, 10 cases of T3, and 9 cases of T4. There were 7 cases of N0, 7 cases of N1, 8 cases of N2 and 7 cases of N3. The staging of patients with NEF was higher than that of patients without NEF. Especially tumor lymphovascular invasion rate was 82.8%. The overall survival of patients with gastric cancer characterized by NEF was 73.8 months. CONCLUSIONS: Positive NEF status might be correlated with clinicopathologic parameters such as a high stage and high frequency of regional lymph node metastasis.