Gastric neuroendocrine tumors display deep invasive features, with amorphous pit and irregular vascular pattern, using narrow-band imaging and magnification

To the best of our knowledge, gastric neuroendocrine tumors are rare, usually diagnosed with endoscopic ultrasound [1], and their endoscopic aspect has rarely been described in the literature [2].

We present the case of a 71-year-old man who was referred for endoscopic submucosal dissection (ESD) of a gastric neuroendocrine tumor, 2 cm in size and without secondary lesions. The patient had previously been diagnosed with Biermer disease with gastric atrophy, and refused surgery for the tumor.

Gastroscopy showed a 2-cm nodular submucosal lesion, with ulceration to the top and lateral aspect, in the anterior part of the fundus ([Fig. 1 a, c]). Within the ulcerated zone, a clearly demarcated area appeared. Initially, this area was covered with a thick mucus cap, which was easily washed using a peristaltic pump.

Fig. 1 Endoscopic aspect of gastric neuroendocrine tumor. a Submucosal nodular aspect with two ulcerations. b Narrow-band imaging (NBI) aspect before removing the mucus cap. c White-light aspect after removing the cap, revealing red vessels. d NBI aspect with amorphous mucosal pattern and irregular “spark-like” capillary vessels (arrow).

Narrow-band imaging with dual focus magnification showed absence of pit pattern and presence of large amorphous areas, as described by Kudo as a Vn pit pattern [3]. The vascular pattern was composed of high-density straight and “spark-like” capillary vessels, without any avascular areas. This vascular pattern was clearly irregular, as described by Sano’s classification as a type 3a pattern ([Fig. 1 b, d]) [4].

We performed ESD with large safety margins, without any adverse events ([Video 1]). Pathological examination ([Fig. 2]) showed a 5.5-cm specimen containing a nodular lesion of 2.7 cm, with safe margins. A grade 1 neuroendocrine tumor was diagnosed. The multidisciplinary team considered the resection to be curative; only follow-up with computed tomography scan to assess for lymph node involvement was indicated.

Video 1 Endoscopic aspect and endoscopic submucosal dissection of a grade 1 gastric neuroendocrine tumor.

Fig. 2 Pathology examination. a Endoscopic submucosal dissection specimen. b Macroscopic pathology examination. c Hematoxylin and eosin stain (× 12 magnification). d Immunohistochemistry chromogranin A (× 12 magnification). e Immunohistochemistry Ki 67 (× 12 magnification).

This case illustrates the specific endoscopic aspect of gastric neuroendocrine tumors when ulcerated, and the ability to cure such tumors safely with ESD without always having to use full-thickness resection devices [5].

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• References

• 1 Rösch T, Lorenz R, Dittler HJ. [Endoscopic ultrasound in gastroenterologic tumors]. Fortschr Med 1991; 109: 553-558
• 2 Gheorghe A-V, Rimbas M, Ginghina O. et al. An atypical type I gastric neuroendocrine tumor. Rom J Intern Med 2017; 55: 253-256
• 3 Kudo S, Rubio CA, Teixeira CR. et al. Pit pattern in colorectal neoplasia: endoscopic magnifying view. Endoscopy 2001; 33: 367-373
• 4 Uraoka T, Saito Y, Ikematsu H. et al. Sano’s capillary pattern classification for narrow-band imaging of early colorectal lesions. Dig Endosc 2011; 23 (Suppl. 01) 112-115
• 5 Kappelle WFW, Backes Y, Valk GD. et al. Endoscopic full-thickness resection of gastric and duodenal subepithelial lesions using a new, flat-based over-the-scope clip. Surg Endosc 2017; DOI: 10.1007/s00464-017-5989-8.