OBJECTIVETo analyze the clinicopathological features of intestinal neuroendocrine neoplasms.

METHODSThe clinicopathological features of 114 patients with intestinal neuroendocrine neoplasms treated in our hospital from April 1999 to March 2011 were retrospectively reviewed, including tumor location, histological classification, muscle invasion, metastasis and clinical data. Immunohistochemical SP staining was applied to examine the expression of 15 markers in the tumor specimens.

RESULTSThe male:female ratio of the patients was 1.33, and most of the tumors were located in the rectum of polypoid type. The positive rate of immunohistochemical staining of Syn expression was 97.4%, NSE 95.6%, PGP9.5 84.2%, CD56 75.4%, CD57 72.8%, CgA 43.0%, S100 36.0%, Syn combined with CgA 99.1%, and the two marker Syn and CgA combined with any one of CD56, CD57 or PGP9.5 reached to 100%. The 5-years survival rates of G1, G2 were 98.9% and 76.9%, respectively, and the overall 5-year survival rate of intestinal neuroendocrine neoplasms was 92.9%. Two of the 7 cases of poor differentiated neuroendocrine carcinoma died after operation, another 2 of them lost to follow up. Others were still alive during the follow-up. Among the 3 patients with small cell carcinoma, two survived for 8 to 24 months after operation, and one lost to follow up. Two cases of mixed adenoneuroendocrine carcinoma (MANEC) were still surviving during the follow-up. Different histological types of intestinal neuroendocrine neoplasms were significantly different in sex, primary tumor site, pathological type, tumor size, types of combined tumors, pT stage, aggressive nervous and vascular invasion, and metastasis (all P < 0.05). Single factor analysis of the intestinal neuroendocrine neoplasms indicated that tumor size (Z = -6.334, P < 0.001), histological classification (χ(2) = 31.175, P < 0.001) and muscle invasion (χ(2) = 63.567, P < 0.001) were associated with metastasis of intestinal neuroendocrine neoplasms. Logistic analysis showed that muscle invasion was the main behavior risk factor of this tumor (OR = 1.827, P < 0.05).

CONCLUSIONSIntestinal neuroendocrine neoplasms usually occur in males, and the most common involved organ is the rectum. Their histological types are related to the prognosis, and the depth of invasion is an important metastasis factor of intestinal neuroendocrine neoplasms. Of the neuroendocrine makers, the combination of CgA and Syn shows a higher diagnostic sensitivity.