Neuroendocrine carcinoma of the colon. Correct diagnosis is important.

Neuroendocrine carcinomas of the colon and rectum are unusual and have in the past been misrepresented as either carcinoid tumors or undifferentiated cancers. Colorectal neuroendocrine tumors comprise a clinicopathologic spectrum that ranges from indolent to highly aggressive. The case discussed illustrates the importance of the right diagnosis because it will affect treatment and may better predict the clinical course.