Small neuroendocrine tumor of the duodenal bulb: Endoscopic submucosal dissection, laparoscopic and endoscopic cooperative surgery or surgery?

Abstract

Neuroendocrine neoplasms of the gastric tube are less common than adenocarcinomas. Topography includes stomach, small intestine, Vater ampulla, and gross intestine. They are graded as neuroendocrine tumors grade I and II (NETs GI and GII) and neuroendocrine carcinomas GIII based on Ki-67 index and mitotic count.[1] Endoscopic treatment for GI NETs ≤1 cm that does not extend beyond the submucosal layer and does not demonstrate lymph node metastasis is recommended. Tumors ≥2 cm, with lymph node metastasis, are indicated for surgical treatment. The treatment strategy for tumors between 10 and 20 mm in size remains controversial.[2] We present a rare case of a 60-year-old male patient with end-stage renal failure who underwent a screening pretransplantation endoscopic control. Colonoscopy had no pathological findings. Gastroscopy reveals an abnormal mucosa in the anterior upper part of the duodenal bulb that was described as a micronodular mucosa and a central nodule of 6 mm with erythematous mucosa. Histology of the micronodular mucosa reveals a heterotopic gastric mucosa and a small hyperplastic polyp. Biopsies from the nodule reveal a carcinoid tumor (NET GI). Immunohistochemistry: Positive chromogranin levels, low mitotic index (1/10 HPF), and Ki-67 index <1% [Figure 2]. Gastrin levels were normal and chromogranin levels were abnormal (314 ng/ml, ULN <120 ng/ml). Spiral tomography of the thorax and the abdomen were normal. Endoscopic submucosal dissection is indicated for small NETs (≤1 cm). Laparoscopic and endoscopic cooperative surgery is a novel method, but the experience is limited. Surgery is the best choice for large NETs (>2 cm) and those of the duodenal bulb with histological extensions and the lack of assessing depth invasion.