Mixed large cell neuroendocrine carcinoma with squamous cell carcinoma of the rectum: Report of a rare case and review of the literature()

INTRODUCTION: Mixed large cell neuroendocrine neoplasms of the rectum are rare and aggressive neoplasms. Survival is poor due to the high rate of lymph node metastases and distant metastases at the time of diagnosis. PRESENTATION OF CASE: We report a case of a 50-year-old male patient with a mixed large cell neuroendocrine carcinoma with squamous cell carcinoma of the rectum located 8 cm from the anal verge, treated with low anterior resection and total mesorectal excision with free surgical margins. There were lymph nodes metastases but no distant metastases at the time of diagnosis. The patient refused to receive adjuvant chemotherapy and died 6 months later due to liver failure as a result of multiple hepatic metastases. DISCUSSION: There are not known predisposing factors for the development of neuroendocrine rectal carcinoma. A neuroendocrine carcinoma of the rectum is a rare tumor with an incidence of less than 0.1% of all colorectal malignancies. The median survival ranges from 5 to 10.4 months in several studies and there are not sufficient data in bibliography about ideal adjuvant therapy after resection of mixed squamous large cell neuroendocrine carcinoma of the rectum. CONCLUSION: Low anterior resection and total mesorectal excision with free surgical margins in the presence of lymph nodes metastasis is not a sufficient treatment for rectal neuroendocrine carcinoma. More studies should be done in order to determine the ideal adjuvant treatment of these rare and aggressive tumors.