A Case of Cecal Neuroendocrine Carcinoma with Foci of Adenocarcinoma and Squamous Cell Carcinoma

We experienced a case of cecal neuroendocrine carcinoma with foci of adenocarcinoma and squamous cell carcinoma. Macroscopically it was a typical type 2 cancer, but microscopically it was divided into two areas, neuroendocrine carcinoma and adenocarcinoma. In the neuroendocrine carcinoma area, much squamous differentiation was observed. In immunohistochemical studies, the tumor was positive for neuron-specific enolase but negative for chromogranin A staining. Since definite diagnosis could not be obtained by immunohistochemical studies, electron microscopic study was added. It revealed dense-core granules, and we arrived at a final diagnosis of neuroendocrine carcinoma. The patient, a 63-year-old woman had a liver metastasis in segment No.4 and underwent right colectomy (D2) and partial resection of the liver simultaneously. She died nine months after the operation because of remnant liver tumor recurrence. This poor outcome is very similar to that in other reports on neuroendocrine carcinoma. We reported this case because its pathological findings are very diverse and quite suggestive in terms of its origin and tumor cell differentiation.