Endoscopic Findings and Treatment of Gastric Neoplasms in Familial Adenomatous Polyposis

Abstract

Purpose: Gastric neoplasia is a common manifestation of familial adenomatous polyposis (FAP). This study aimed to elucidate the clinical characteristics, endoscopic features including fundic gland polyposis (FGPsis), and treatment outcomes of gastric neoplasms (GNs) in patients with FAP.

Materials and methods: A total of 35 patients diagnosed with FAP, including nine patients from four pedigrees who underwent esophagogastroduodenoscopy (EGD), were investigated regarding patient characteristics, GN morphology, and treatment outcomes.

Results: Twenty-one patients (60.0%) had 38 GNs; 33 (86.8%) and 5 (13.2%) were histologically diagnosed with adenocarcinoma and adenoma, respectively. There were no specific patient characteristics related to GNs. Nodule-type GNs were more prevalent in patients with FGP than without (52.2% vs. 0.0%, P=0.002) in the upper body of the stomach. Conversely, depressed-type GNs were fewer in patients with FGPsis than in those without (13.0% vs. 73.3%, P<0.001). Slightly elevated-type GNs were observed in both groups (34.8% vs. 20.0%, P=0.538). Even within pedigrees, the background gastric mucosa and types of GNs varied. In total, 24 GNs were treated with endoscopic submucosal dissection (ESD) and eight with endoscopic mucosal resection (EMR). EMR was selected for GNs with FGPsis because of the technical difficulty of ESD, resulting in a lower en bloc resection rate (62.5% vs. 100%, P=0.014).

Conclusions: Our study indicates the necessity of routine EGD surveillance in patients diagnosed with FAP. Notably, the morphology and location of GNs differed between patients with and without FGPsis. Endoscopic treatment and outcomes require more attention in cases of FGPsis.

Keywords: Endoscopic mucosal resections; Endoscopic submucosal dissections; Familial adenomatous polyposis; Gastric neoplasms.

Fig. 1. Representative endoscopic images of fundic gland polyposis, carpeting, and polypoid mound.

(A) Fundic gland polyposis: a stomach with over 100 fundic gland polyps. (B) Carpeting: the fundus and proximal body of the stomach covered in polyps without any intervening visible normal mucosa. (C) Polypoid mound: one large polyp or a collection of polyps over 2 cm in carpeting.

Fig. 2. Representative endoscopic images of GNs.

(A) A nodule-type GN in the upper body of the stomach in patients with FGPsis. (B) Histopathological image of the nodule-type GN in a low-power field. Foveolar-type gastric adenocarcinoma can be seen on the pyloric gland adenoma. (C) Magnified image of the area surrounded by a green rectangle. Dense irregular papillary glands can be observed in the adenocarcinoma. (D) A depressed-type GN is frequently seen in the lower body of the stomach in patients without FGPsis. (E) Histopathological image of the depressed-type GN in a low-power field. (F) Magnified image of the area surrounded by a red rectangle. Dense irregular glands and increased nuclear density can be seen in the tumor. Furthermore, a proliferative zone can be observed in the shallow mucosa. This case was diagnosed as a well-differentiated adenocarcinoma. (G) A slightly elevated-type GN is seen in both groups. (H) Histopathological image of the slightly elevated-type GN in a low-power field. Dense dysplastic glands with nuclear pseudostratification can be seen. This case was diagnosed as a well-to-moderately differentiated adenocarcinoma. (I) Magnified image of the area surrounded by a yellow rectangle. Fundic glands and dilated foveolar glands can be seen in the deep layer of the mucosa. GN = gastric neoplasm; FGPsis = fundic gland polyposis.

Fig. 3. GC recurrence after EMR.

(A) A reddish nodule-type lesion (white arrow) in the upper body of the stomach, resected by EMR. (B) A well-differentiated adenocarcinoma with a positive lateral resection margin. (C) A reddish flat-elevated lesion with a central depression on the oral side of the EMR. (D) The biopsy specimen from the lesion shows a well-differentiated adenocarcinoma. Computed tomography image showing liver metastasis. (A, B) The white circle and triangle compare the endoscopic images before and after the detection of advanced GC. GC = gastric cancer; EMR = endoscopic mucosal resection.