Risk factors of lymph node metastasis in patients with gastric neuroendocrine tumor with normal serum gastrin level.

Background/aims: Locoregional gastric carcinoids with normal serum gastrin level have been recommended radical resection regardless of tumor size or depth of invasion. However, there have been some reports which showed small sporadic gastric carcinoids could be treated with local resection. The aim of this study was to elucidate risk factors of lymph node metastasis in patients with gastric carcinoids with normal serum gastrin level and determine the indications for limited resection such as endoscopic treatment.

Methodology: We performed clinicopathologic reviews of thirty gastric carcinoids with normal serum gastrin level from January 1996 to December 2010.

Results: One case show distant metastasis and two cases showed lymph node metastasis at the time of diagnosis. For twenty seven cases which showed no regional lymph node or distant metastasis initially no additional lymph node or distant metastasis were diagnosed throughout the follow up period. Large tumor size (>10 mm), proper muscle infiltration, WHO classification grade 2 and lymphovascular invasion was noted risk factor of lymph node metastasis by univariate logistic regression analysis.

Conclusions: Small (≤10 mm) gastric carcinoids with normal serum gastrin level confined to submucosa can be treated with endoscopic or local resection unless lymphovascular invasion.