Gastric adenocarcinoma of fundic gland mucosa type localized in the submucosa

Abstract

Rationale:Gastric adenocarcinoma of fundic gland type (GA-FG) is a new histological type of gastric cancer manifesting with differentiation into a fundic gland. Furthermore, gastric adenocarcinoma of fundic gland mucosa type (GA-FGM) is a tumor that shows differentiation into not only a fundic gland but also foveolar epithelium and a mucous gland. These tumors tend to invade the submucosal layer. However, no cases of these tumors being localized only in the submucosa have been reported. Here, we present a case of GA-FGM localized in the submucosa and describe the cytological features of this tumor. To our knowledge, this is the first reported case of GA-FGM localized in the submucosa.Patient concerns:A man in his early 70s was referred to our institution because of the detection of a gastric submucosal tumor during a health checkup.Diagnoses:Gastric adenocarcinoma of fundic gland mucosa type.Interventions:Endoscopic ultrasound-guided fine-needle aspiration (FNA), endoscopic submucosal dissection (ESD), and total gastrectomy with lymph node dissection were performed.Outcomes:The FNA specimen showed epithelial cells with low-grade atypia. In the ESD specimen, adenocarcinoma showing a gastric fundic gland mucosa-like morphology was observed. Immunohistochemical analysis showed positive staining for pepsinogen I, H+/K+-adenosine triphosphatase, MUC6, and MUC5AC and negative staining for MUC2 and CD10, indicating tumor differentiation into fundic gland mucosa. Therefore, the tumor was diagnosed as GA-FGM, with localization in the submucosal layer. Total gastrectomy and lymph node dissection were performed because of the positive margins of the ESD specimen. Neither residual tumor nor lymph node metastasis was detected; however, many foci of heterotopic gastric glands (HGGs) were observed in the gastric wall, suggesting that GA-FGM arose from an HGG. After treatment, no recurrence was observed during a 1-year follow-up period.Lessons:Various tumors may arise from HGGs. Furthermore, when an FNA specimen shows gastric fundic gland mucosa-like epithelial cells with weak atypia, the possibility of GA-FG and GA-FGM should be considered.

Gastric adenocarcinoma of the fundic gland type: clinicopathological features of eight patients treated with endoscopic submucosal dissection

“…Among the cases with follow-up data, one patient died of carcinomatosis 22 and three showed disease recurrence 10,23 , which may have been due to incomplete excision of the lesion. Complete surgical excision and fundectomy for some cases 24,25 , and ESD or EMR for most cases appear to be adequate and may lead to remission. In our study, all patients could be followed up after ESD for a period from 5-33 months.…”

Gastric adenocarcinoma of fundic gland type arising from heterotopic gastric glands during a 19-year follow-up period

“…HGG and gastric adenocarcinoma develop as a result of repeated erosion and regeneration of the mucosa, and this fact suggests that HGG is a paracancerous lesion [11–13]. Only two case reports have shown GAFG to be associated with HGG [3, 4]. In one of these reports, the patient had tested positive for MUC5AC and was diagnosed with GAFGM [4].…”

“…Only two case reports have shown GAFG to be associated with HGG [3, 4]. In one of these reports, the patient had tested positive for MUC5AC and was diagnosed with GAFGM [4].…”

“…However, as several case reports of GAFG were published, some showed high-degree atypia and high-grade malignancy [1, 2]. Heterotopic gastric gland (HGG) is a paracancerous lesion, and two case reports have shown GAFG co-existing with HGG [3, 4].…”

The pathology of gastric and duodenal polyps: current concepts

“…34 Microscopically, OGAs can display a chief cell-predominant pattern, an admixture of chief and parietal cells resembling normal fundic glands, and a predominant mucous neck cell and foveolar differentiation pattern. 34,57,58 The latter subtype is usually observed in larger lesions, which could represent a more aggressive variant. 34 Architecturally, OGAs are composed of tightly packed tubules and trabeculae.…”