Two rare gastric hamartomatous inverted polyp cases suggest the pathogenesis of growth

Clinicopathologic and endoscopic characteristics of ten patients with gastric hamartomatous inverted polyp: a single center case series

BACKGROUND

Gastric hamartomatous inverted polyps (GHIPs) are not well characterized and remain diagnostically challenging due to rarity. Therefore, this study aims to investigate the clinicopathologic and endoscopic characteristics of patients with GHIP.

METHODS

We retrospectively reviewed clinicopathologic and endoscopic features of ten patients with GHIP who were admitted to Beijing Friendship Hospital from March 2013 to July 2022. All patients were treated successfully by endoscopic resection.

RESULTS

GHIPs were usually asymptomatic and found incidentally during gastroscopic examination. They may be sessile or pedunculated, with diffuse or local surface redness or erosion. On endoscopic ultrasonography, the sessile submucosal tumor-type GHIP demonstrated a heterogeneous lesion with cystic areas in the third layer of the gastric wall. Histologically, GHIPs were characterized by a submucosal inverted proliferation of cystically dilated hyperplastic gastric glands accompanied by a branching proliferation of smooth muscle bundles. Inflammatory cells infiltration was observed in the stroma, whereas only one patient was complicated with glandular low-grade dysplasia. Assessment of the surrounding mucosa demonstrated that six patients (60%) had atrophic gastritis or Helicobacter pylori-associated gastritis, and four patients (40%) had non-specific gastritis. Endoscopic resection was safe and effective.

CONCLUSIONS

GHIPs often arise from the background of abnormal mucosa, such as atrophic or H.pylori-associated gastritis. We make the hypothesis that acquired inflammation might lead to the development of GHIPs. We recommend to make a full assessment of the background mucosa and H. pylori infection status for evaluation of underlying gastric mucosal abnormalities, which may be the preneoplastic condition of the stomach.

Diagnosis and treatment of gastric hamartomatous inverted polyp (GHIP) by endoscopic submucosal dissection: A case report

RATIONALE

Gastric hamartomatous inverted polyps (GHIP) is not a common disease, and it has rarely been reported in the literature. Preoperative diagnosis is difficult due to the deep position and surface covered with normal gastric mucosa. However, with the progress of endoscopic technology, endoscopic submucosal dissection (ESD) can play a crucial role in the diagnosis and treatment of GHIP.

PATIENT CONCERNS

A 61-year-old Chinese man underwent gastroscopy due to abdominal pain 2 months prior that revealed chronic superficial nonatrophic gastritis with erosion and a submucosal tumor in the gastric body (an ultrasound gastroscopy was recommended). Therefore, he was admitted to our hospital for further diagnosis and treatment.

DIAGNOSES

A hemispherical submucosal tumor was found in the middle segment of the stomach, with a size of approximately 30 mm × 35 mm and a smooth surface without central ulceration or mucosal bridge formation. Ultrasound gastroscopy showed that the lesion was a hypoechoic mass with uniform internal echo originating from the muscularis propria.

INTERVENTIONS

The tumor was completely removed by using ESD. The postoperative pathological results indicated a monocystic structure in the submucosa that was not connected with the surface mucosa. The surface of the cyst was covered with foveolar cells and mucous-neck cells (part of which had low-grade intraepithelial neoplasia), and GHIP was considered to be diagnosed.

OUTCOMES

According to the abovementioned endoscopic and pathological features, the patient was finally diagnosed with GHIP. The patient was successfully discharged after surgery and received regular follow-up observations.

LESSONS

GHIP is located in the submucosa layer and has the potential risk of malignant transformation. However, it is not easy to diagnose by using gastroscopy and ultrasound gastroscopy. ESD can obtain complete specimens, which contributes to the diagnosis and treatment of GHIP.

Autoimmune gastritis with a gastric hamartomatous inverted polyp and two hyperplastic polyps: a case report

We report an unusual case of autoimmune gastritis (AIG) complicated with a submucosal tumor (SMT) and two pedunculated polyps in a 60-year-old man. The patient was admitted for epigastric distention, heartburn, and anorexia. Endoscopy showed an SMT in the fundus, two pedunculated polyps in the body, and markedly atrophic mucosa of the body and fundus. The SMT, measuring 20 mm in diameter, was resected by endoscopic submucosal dissection and histologically diagnosed as a gastric hamartomatous inverted polyp (GHIP), which is characterized by submucosal glandular proliferation, cystic dilatation, and calcification. The gland structures consisted of foveolar cells and pseudopyloric or mucous-neck cell types. The two pedunculated polyps that were resected by endoscopic mucosal resection were histologically diagnosed as hyperplastic polyps, which are characterized by hyperplastic foveolar glands with pseudopyloric or mucous-neck glands in the inflamed stroma in the mucosa, which consisted of almost the same types of lining cells as the GHIP in the fundus. Findings may indicate the relationship between GHIP, hyperplastic polyp, and AIG. We highlight considering GHIP as a differential diagnosis for an SMT in patients with AIG.

Gastric hamartomatous inverted polyp: Report of three cases with a review of the endoscopic and clinicopathological features

Objectives

A gastric hamartomatous inverted polyp (GHIP) is a rare submucosal tumor characterized histopathologically by a submucosal inverted proliferation of cystically dilated hyperplastic gastric glands. Only 42 GHIPs have been reported in English literature. Few GHIPs have been reported to accompany adenocarcinomas. We reported on three patients with a GHIP and reviewed the clinicopathological and endoscopic features of GHIPs.

Methods

This study included two men and one woman with a GHIP. The endoscopic, histopathological, and immunohistochemical features of the endoscopically resected specimens were analyzed. A gene mutation analysis was also performed.

Results

All the tumors were located in the body of the stomach, with a median size of 20 mm. Two tumors were sessile, and the remaining tumor had a pedunculated appearance. The overlying mucosa mainly appeared normal but was reddish in one tumor. The histopathological examination of the tumors revealed a well-circumscribed and lobular submucosal proliferation of cystically dilated hyperplastic glands. The immunohistochemical analysis revealed that the MUC5AC-positive foveolar epithelium was located in the center, and MUC6-positive pseudo-pyloric or pepsinogen-I and H⁺/K⁺ ATPase-positive fundic-type glands were located at the periphery of two tumors. No carcinomatous components were noted in any of the tumors. Moreover, no significant mutations in oncogenes or tumor suppressor genes were noted.

Conclusions

Our review revealed that approximately three fourths of GHIP cases showed an submucosal tumor-like feature, whereas endoscopic features, including the endoscopic ultrasonography findings, were not characteristic. Because an endoscopic diagnosis of a GHIP may be difficult, complete endoscopic resection may be required for a pathological diagnosis.

Gastric Inverted Polyps-Distinctive Subepithelial Lesions of the Stomach: Clinicopathologic Analysis of 12 Cases With an Emphasis on Neoplastic Potential

Gastric inverted polyps (GIPs) are rare gastric polyps characterized by a submucosal inverted growth of mucosal components. Because of their rarity, they are not well characterized and are diagnostically challenging. We examined 12 cases of GIPs arising in 8 male and 4 female patients (mean age: 56 y). Most GIPs (11/12, 92%) occurred as a single, rounded subepithelial lesion in the body or fundus (mean size: 14.9 mm). Histologically, GIPs consisted of gastric-type glandular epithelium and smooth muscle component, growing in an endophytic manner; however, they displayed significant morphologic variations. We classified GIPs into 3 subtypes by the following features: communication with the mucosal surface, smooth muscle boundary, and tissue organization. The defining characteristics of type 1 were a mucosal communicating structure at the center and a well-defined smooth muscle boundary, resulting in a characteristic low-magnification morphology of a round vase. Type 2 had an organized glandular proliferation with smooth muscle boundary and no central communicating structure. Type 3 GIPs had no mucosal communicating structure or smooth muscle boundary; its key histologic feature was the lobular organization pattern produced by proliferations of cystic or hyperplastic glands and smooth muscle. All type 1 GIPs exhibited coexisting adenocarcinoma (3 cases) or stromal proliferation (3 cases). Three patients with type 2 GIP had separate adenocarcinoma. None of the type 3 GIPs had accompanying carcinoma. In conclusion, GIPs are a heterogenous group showing different morphology and clinical behavior. Notably, type 1 GIP could be considered a precancerous lesion with the potential to develop adenocarcinoma.

Diagnosis and treatment of gastric hamartomatous inverted polyp (GHIP) using a modified combination of laparoscopic and endoscopic approaches to neoplasia with a non-exposure technique (modified CLEAN-NET): a case report

BACKGROUND

Gastric hamartomatous inverted polyp (GHIP) is a pathological condition where enlarged gastric glands with cystic dilatation grow in the submucosa. It is difficult to excise the tissue due to its location. In addition, even if the tissue is taken correctly, making an accurate diagnosis is difficult due to foveolar epithelium in the tissue, which can be misdiagnosed as gastric mucosal epithelium. Thus, an accurate diagnosis of GHIP is rarely established from a biopsy alone preoperatively. We here report a case of GHIP with a central dimple, which was diagnosed and treated using a modified combination of laparoscopic and endoscopic approaches to neoplasia with a non-exposure technique (modified CLEAN-NET).

CASE PRESENTATION

A 60-year-old man with a submucosal tumor (SMT) in the stomach was referred to our hospital by a primary care doctor. On examination, a gastrointestinal stromal tumor was suspected. Modified CLEAN-NET was performed for diagnostic and therapeutic purposes. The histopathological examination of the resected specimen showed an enlarged gland duct in the submucosal layer. This finding, along with immunostaining results, led to the diagnosis of GHIP. The postoperative course was uneventful without any symptoms.

CONCLUSIONS

GHIP should be considered among the differential diagnoses of SMT of the stomach. Modified CLEAN-NET may be beneficial in the removal of SMTs such as GHIP with a central dimple because it can avoid stomach deformation of the stomach and tumor dissemination.

A disconcerting false gastric diverticulum mimicking malignancy

Gastric diverticula are the most uncommon form of gastrointestinal diverticula. They can either be of true or false type with different pathogenesis. They may be very challenging to diagnose as symptoms are nonspecific and imaging can simulate a malignant lesion. We report an unusual case of pre-pyloric diverticulum in a 69-year-old man, leading to severe gastric obstruction with a poor general condition. As subsequent endoscopy and imaging were alarming and couldn't exclude malignancy, the patient underwent an antrectomy. The final diagnosis was made on pathological examination. We discuss, through this case, the clinical and pathological features of gastric diverticula with an emphasis on the pathogenesis of this rare entity and the risk of a malignant transformation.

A case of gastric hamartomatous inverted polyp resected endoscopically

We report the case of a 55-year-old woman with a tumor in the greater curvature of the upper gastric body. The tumor was incidentally found on an upper gastrointestinal X-ray series performed during a routine medical examination. Whereas endoscopy revealed a gastric submucosal tumor (SMT), endoscopic ultrasonography demonstrated a heterogeneous tumor with small, cystic, hypoechoic spots originating from the second layer. The patient was clinically asymptomatic, with no contributory family history or abnormal laboratory data. The results of a physical examination, abdominal computed tomography, and plain chest radiography were all unremarkable. Although the endoscopic tumor type was determined to be SMT, the tumor was successfully resected by endoscopic submucosal dissection (ESD) and subsequently diagnosed as a gastric hamartomatous inverted polyp (GHIP). The findings of the present case highlight the importance of considering GHIP as a diagnosis and indicate the utility of en bloc resection of GHIP with ESD.

Gastric inverted hyperplastic polyp: A rare cause of iron deficiency anemia

Gastric inverted hyperplastic polyp (IHP) is a rare gastric polyp characterized by the downward growth of hyperplastic mucosal components into the submucosal layer. Macroscopically, a gastric IHP resembles a subepithelial tumor (SET); as a result, accurately diagnosing gastric IHP is difficult. This issue has clinical significance because gastric IHP can be misdiagnosed as SET or as malignant neoplasm In addition, adenocarcinoma can accompany benign gastric IHP. Although in most cases, gastric IHPs are asymptomatic and are found incidentally, these polyps may cause anemia secondary to chronic bleeding. Here, we report one case involving gastric IHP accompanied by chronic iron deficiency anemia that was successfully managed using endoscopic submucosal dissection.

Gastric Hamartomatous Polyps-Review and Update

Gastric polyps are frequently encountered on endoscopic examinations. While many of these represent true epithelial lesions, some of the polyps may result from underlying stromal or lymphoid proliferations or even heterotopic tissue. Histologic examination is essential for accurate typing of the polyps to predict malignant potential and underlying possible genetic abnormalities. The focus of this review is on gastric hamartomatous polyps, which are relatively rare and diagnostically challenging. Though most of the gastric hamartomatous polyps are benign, certain types are associated with increased malignant potential. These include certain polyps associated with specific genetic familial polyposis syndromes and gastric inverted hamartomatous polyps. Identification of these polyps can result in the prevention or early diagnosis of gastric carcinoma and also help in the identification of family members with polyposis syndromes. The aim of this review is to categorize gastric hamartomatous polyps and aid in the identification of high-risk categories.