A Multifocal Pattern of Neuroendocrine Neoplasms Along the Appendix: A Series of Six Cases.

We present 6 cases with multifocal appendiceal neuroendocrine tumors, including their clinical and histopathological findings. To our knowledge, this is the first description of a multifocal pattern of a neuroendocrine neoplasm arising in the appendix. All patients presented in a setting requiring an acute appendectomy. The number of tumors ranged from 2 to 5. Histopathological examination revealed WHO (World Health Organization) grade 1 tumor in 3 patients and WHO grade 2 in the other 3 patients. The median duration of follow-up in these patients was 70 months (range = 6-192 months). No metastatic disease was observed. According to these findings, a multifocal pattern of neuroendocrine neoplasms along the appendix seems not to be a predictor for local advanced or metastatic disease.