Neuroendocrine tumor in gastric adenoma: a diagnostic pitfall mimicking invasive adenocarcinoma.
Neuroendocrine tumor (NET) in adenoma of the gastrointestinal tract is a rare mixed glandular-endocrine neoplasm and has uncommonly been described mostly in the colon. Histologically, this tumor is composed of a predominant proportion of benign adenomatous component and a small portion of well-differentiated NE component. Only three cases of NET in gastric adenoma have been reported in the literature. We present 4 cases of NET in gastric adenoma mimicking invasive adenocarcinoma. The NETs were 0.62 mm to 4.1 mm in size and located at the basal lamina propria, muscularis mucosa and submucosa. Histologically, NETs consisted of nests, cords, tubules, and clusters of cells that predominantly interposed between the foveolar base without disturbing the overall polyp architecture. The lesions were completely removed by endoscopic submucosal dissection in three cases and in one case, subtotal gastrectomy was performed because endoscopic biopsy was invasive adenocarcinoma. The patients' clinical course was uneventful without an evidence of recurrence or metastasis. The recognition of NET in gastric adenoma will help avoid potential diagnostic pitfalls masquerading as invasvie adenocarcinomas posed by their infiltrative pattern into submucosa. Virtual slides: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1688552293761001.
Department of Pathology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
Sun-Mi
SM
Lee
Soomin
S
Ahn
Yun Kyung
YK
Lee
Kee-Taek
KT
Jang
Cheol Keun
CK
Park
Kyoung-Mee
KM
Kim
D000230:Adenocarcinoma / Q000473:pathology* / Q000601:surgery; D018256:Adenomatous Polyps / Q000473:pathology* / Q000601:surgery; D000368:Aged; D001706:Biopsy; D003937:Diagnosis, Differential; D005743:Gastrectomy; D005773:Gastroscopy; D006801:Humans; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D018193:Neoplasms, Complex and Mixed / Q000473:pathology* / Q000601:surgery; D018358:Neuroendocrine Tumors / Q000473:pathology* / Q000601:surgery; D011237:Predictive Value of Tests; D013274:Stomach Neoplasms / Q000473:pathology* / Q000601:surgery; D016896:Treatment Outcome