Gastric extremely well-differentiated intestinal-type adenocarcinoma: a challenging lesion to achieve complete endoscopic resection

Case report: A rare case of very well-differentiated gastric adenocarcinoma of gastric type with a lymphovascular invasion

Background

Very well-differentiated gastric adenocarcinoma (VWDA) is a rare variant of gastric cancer, for which the diagnostic criteria and clinical behavior are not fully established. We reported a case of an intramucosal VWDA of gastric type with a lymphovascular invasion (LVI).

Case presentation

A 67-year-old female was diagnosed as intramucosal gastric adenocarcinoma after a biopsy at the local hospital 3 weeks ago and then visited our hospital for further treatment. The endoscopic examination in our hospital showed a rough, slightly faded, 30-mm, flat, and elevated lesion on the lesser curvature of the middle gastric body. Histopathologically, the lesion consisted of superficial foveolar-type papillary adenocarcinoma and deep pyloric gland-type tubular adenocarcinoma. The immunostaining results showed that the foveolar-type papillary adenocarcinoma was positive for MUC5AC and had a high index of Ki-67, but the pyloric gland-type tubular adenocarcinoma was positive for MUC6 and had a low index of Ki-67. Both components were negative for MSH2 and MSH6, which suggested the high microsatellite instability phenotype. Moreover, a LVI was detected in the lesion. The pathological diagnosis was VWDA of gastric type.

Conclusion

The case has unique histological and immunophenotypic characteristics, which not only indicates the importance of architectural features in the diagnosis of VWDA but also further proves that the aggressive behavior of VWDA is correlated with tumor histological type and immunophenotype.

Clinical pathological characteristics of "crawling-type" gastric adenocarcinoma cancer: A case report

BACKGROUND

Gastric cancer (GC) is a significant health problem worldwide, and early detection and accurate diagnosis are crucial for improving patient outcomes. Crawling-type gastric adenocarcinoma is a rare subtype of GC that has unique histopathological and clinical characteristics, and its diagnosis and management can be challenging. This pathological type of GC is also rare.

CASE SUMMARY

Here, we report the case of a patient who underwent ordinary endoscopy, narrow-band imaging, and endoscopic ultrasonography intending to determine the extent of tumor invasion and upper abdominal enhanced computed tomography and whether there was tumor metastasis. Then, endoscopic submucosal dissection was performed. After pathological and immunohistochemical examination, the pathological diagnosis was crawling-type gastric adenocarcinoma. This is a very rare and special pathological type of tumor. This case highlights the importance of using advanced endoscopic techniques and pathological examination in diagnosing and managing gastric crawling-type adenocarcinoma. Moreover, the findings underscore the need for continued research and clinical experience in this rare subtype of GC to improve patient outcomes.

CONCLUSION

The "crawling-type" GC is a rare and specific tumor pathology. It is difficult to identify and diagnose gliomas via endoscopy. The tumor is ill-defined, with a flat appearance and indistinct borders due to the lack of contrast against the background mucosa. Pathology revealed that the tumor cells were hand-like, so the patient has diagnosed with "crawling-type" gastric adenocarcinoma.

Risk-Scoring System for Prediction of Non-Curative Endoscopic Submucosal Dissection Requiring Additional Gastrectomy in Patients with Early Gastric Cancer

Purpose

When patients with early gastric cancer (EGC) undergo non-curative endoscopic submucosal dissection requiring gastrectomy (NC-ESD-RG), additional medical resources and expenses are required for surgery. To reduce this burden, predictive model for NC-ESD-RG is required.

Materials and Methods

Data from 2,997 patients undergoing ESD for 3,127 forceps biopsy-proven differentiated-type EGCs (2,345 and 782 in training and validation sets, respectively) were reviewed. Using the training set, the logistic stepwise regression analysis determined the independent predictors of NC-ESD-RG (NC-ESD other than cases with lateral resection margin involvement or piecemeal resection as the only non-curative factor). Using these predictors, a risk-scoring system for predicting NC-ESD-RG was developed. Performance of the predictive model was examined internally with the validation set.

Results

Rate of NC-ESD-RG was 17.3%. Independent pre-ESD predictors for NC-ESD-RG included moderately differentiated or papillary EGC, large tumor size, proximal tumor location, lesion at greater curvature, elevated or depressed morphology, and presence of ulcers. A risk-score was assigned to each predictor of NC-ESD-RG. The area under the receiver operating characteristic curve for predicting NC-ESD-RG was 0.672 in both training and validation sets. A risk-score of 5 points was the optimal cut-off value for predicting NC-ESD-RG, and the overall accuracy was 72.7%. As the total risk score increased, the predicted risk for NC-ESD-RG increased from 3.8% to 72.6%.

Conclusions

We developed and validated a risk-scoring system for predicting NC-ESD-RG based on pre-ESD variables. Our risk-scoring system can facilitate informed consent and decision-making for preoperative treatment selection between ESD and surgery in patients with EGC.

Preoperative diagnosis of a gastric extremely well-differentiated adenocarcinoma: A case report

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Gastric extremely well-differentiated adenocarcinoma (EWDA) is a rare type of gastric adenocarcinoma.

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It is very difficult to preoperatively diagnose gastric EWDA presenting as an elevated lesion appearing like a submucosal tumor.

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This is the first report of a gastric EWDA appearing like a submucosal tumor diagnosed by preoperative endoscopic submucosal dissection.

Introduction

Gastric adenocarcinomas with low grade atypia may be difficult to diagnose as gastric cancer by preoperative biopsy. We report an extremely well-differentiated adenocarcinoma (EWDA) of the stomach which appeared like a submucosal tumor diagnosed by preoperative endoscopic submucosal dissection.

Presentation of case

A 70-year-old male was referred with a 3-month history of a submucosal-appearing lesion in the gastric wall found on endoscopy. Biopsies of the lesion were performed and were inconclusive for neoplasia. Endoscopic ultrasonography showed a low echoic tumor growing into the fourth layer of the gastric wall. It was difficult to identify the tumor by repeat biopsy. Endoscopic submucosal dissection of the lesion was performed and revealed adenocarcinoma, and laparoscopic total gastrectomy was performed. Histopathologic evaluation showed that the tumor was stage IIA (T3N0M0). There is no recurrence 12 months after resection.

Discussion

Gastric EWDAs are rare lesions, accounting for 0.6% of all gastric cancers. It is difficult to diagnose gastric EWDA especially if it appears like a submucosal tumor. This lesion was finally diagnosed by endoscopic submucosal dissection.

Conclusion

Endoscopic submucosal dissection may facilitate establishing the preoperative diagnosis of a tumor thought to be a gastric EWDA based on its endoscopic appearance and pathological findings.

Outcomes of endoscopic submucosal dissection for intestinal-type adenocarcinoma with anastomosing glands of the stomach

BACKGROUND AND AIM

Gastric intestinal-type adenocarcinoma with anastomosing glands (IAAG) is characterized by architectural abnormality with frequent anastomosing glands and low-grade cytologic atypia. Clinicopathologic features and long-term outcomes of endoscopic submucosal dissection (ESD) for IAAG remain unclear.

METHODS

This study included 2828 patients who underwent ESD for early gastric cancers (EGCs) (78 IAAGs [2.6%] and 2893 well-differentiated [WD] or moderately differentiated [MD] EGCs [97.4%]). Clinicopathologic features and short-term and long-term outcomes of ESD for IAAG were reviewed and compared with those for WD or MD EGCs.

RESULTS

Gastric IAAGs were larger and more likely to be confined to the lamina propria than WD or MD EGCs. Histological heterogeneity, flat or depressed lesion and lateral resection margin (LRM) involvement were observed with significantly higher frequencies in IAAGs than in WD or MD EGCs. En bloc with R0 resection and curative resection rates of IAAGs were 79.5% and 73.1%, respectively, and both were significantly lower than those of WD or MD EGCs (93.8% and 82.9%). LRM involvement accounted for 57.1% of the non-curative resection cases in gastric IAAGs. Half of IAAGs with LRM involvement had a crawling pattern at tumor periphery. Among patients undergoing curative ESD for IAAG, no recurrences occurred during a median 52 months of follow-up. No lymph node metastasis was found in any of IAAG patients undergoing additional surgery after ESD.

CONCLUSIONS

Gastric IAAGs have distinct clinicopathologic features from WD or MD EGCs. Given the favorable long-term outcomes after curative resection, ESD can be indicated for early gastric IAAGs.

Treatment for gastric ‘indefinite for neoplasm/dysplasia’ lesions based on predictive factors

BACKGROUND

Gastric ‘indefinite for neoplasm/dysplasia’ (IFND) is a borderline lesion that is difficult to diagnose as either regenerative or neoplastic. There is a need for guidance in the identification of a subset of patients, who have an IFND lesion with a higher risk of malignant potential, to enable risk stratification and optimal management.

AIM

To determine the clinical and pathologic factors for the accurate diagnosis of gastric IFND lesions.

METHODS

In total, 461 gastric lesions diagnosed via biopsy as IFND lesions were retrospectively evaluated. Endoscopic resection (n = 134), surgery (n = 22), and follow-up endoscopic biopsy (n = 305) were performed to confirm the diagnosis. The time interval from initial biopsy to cancer diagnosis was measured, and diagnostic delays were categorized as > 2 wk, > 2 mo, > 6 mo, and > 1 year. The IFND lesions presenting as regenerating atypia (60%) or atypical epithelia (40%) at initial biopsy were adenocarcinomas in 22.6%, adenomas in 8.9%, and gastritis in 68.5% of the cases.

RESULTS

Four clinical factors [age ≥ 60 years (2.445, 95%CI: 1.305-4.580, P = 0.005), endoscopic size ≥ 10 mm (3.519, 95%CI: 1.891-6.548, P < 0.001), single lesion (5.702, 95%CI: 2.212-14.696, P < 0.001), and spontaneous bleeding (4.056, 95%CI: 1.792-9.180, P = 0.001)], and two pathologic factors [atypical epithelium (25.575, 95%CI: 11.537-56.695, P < 0.001], and repeated IFND diagnosis [6.022, 95%CI: 1.822-19.909, P = 0.003)] were independent risk factors for gastric cancer. With two or more clinical factors, the sensitivity and specificity for carcinoma were 91.3% and 54.9%, respectively. Ten undifferentiated carcinomas were initially diagnosed as IFND. In the subgroup analysis, fold change (5.594, 95%CI: 1.458-21.462, P = 0.012) predicted undifferentiated or invasive carcinoma in the submucosal layers or deeper. Diagnostic delays shorter than 1 year were not associated with worse prognoses. Extremely well-differentiated adenocarcinomas accounted for half of the repeated IFND cases and resulted in low diagnostic accuracy even on retrospective blinded review.

CONCLUSION

More than two clinical and pathologic factors each had significant cut-off values for gastric carcinoma diagnosis; in such cases, endoscopic resection should be considered.

Distinct expression profile of key molecules in crawling-type early gastric carcinoma

BACKGROUND

Gastric "crawling-type" adenocarcinoma (CRA) is a tumor histologically characterized by irregularly fused glands with low-grade cellular atypia that tends to spread laterally in the mucosa. To date, the expression characteristics of the key molecules involved in CRA, including receptor tyrosine kinases (RTKs), mismatch repair (MMR) proteins, phosphatase and tensin homolog (PTEN), as well as the Epstein-Barr virus (EBV) status, have yet to be uncovered.

METHODS

We constructed tissue microarrays of 94 CRAs, 72 conventional-type differentiated adenocarcinomas (CDAs), and 71 intramucosal poorly cohesive adenocarcinomas (PCAs) from early gastric cancers to evaluate and compare the pathological and expression profiles of potential key molecules for molecular classification (EBV; four MMR proteins-MLH1, MSH2, PMS2, and MSH6; three RTKs-HER2, MET, and EGFR; PTEN; and p53).

RESULTS

None of the CRAs showed MMR deficiency (0.0 % vs. 5.6 %, CRA vs. CDA, p = 0.036), HER2 overexpression (0.0 % vs. 12.5 %, p = 0.001), or loss of PTEN expression (0.0 % vs. 9.7 %, p = 0.003). Moreover, MET overexpression (4.4 % vs. 19.4 %, p = 0.004), and a mutant p53 pattern (12.4 % vs. 62.5 %, p < 0.001) were significantly less common in CRAs than in CDAs. However, clinicopathological features and all the profile of the molecules of CRAs were close to those of the PCA group.

CONCLUSIONS

CRA demonstrated unique clinicopathological characteristics and showed a distinct expression profile of key molecules, which was close to that of a null phenotype. These results support the classification of CRA as a distinct subgroup of gastric adenocarcinoma.

Clinicopathology of Early Gastric Carcinoma: An Update for Pathologists and Gastroenterologists

BACKGROUND

The WHO defines early gastric carcinoma (EGC) as invasive carcinoma up to the submucosal layer, regardless of nodal metastasis. The recent study results indicate that EGC varies in location, histology, nodal metastasis, and prognosis.

SUMMARY

The heterogeneity in EGC may be related to various types of epithelial stem cells. The most important stem cells include Lgr5+ cells at the base of a gastric unit in the antrum-pylorus-cardia, Mist1+ cells at the isthmus/Troy+ cells at the base in the corpus-fundus, and Sox2+ cells at the base in almost all regions. Dysregulation of these cells along with environmental factors transform stem cells in different regions into malignancy in genetically susceptible populations.

KEY MESSAGE

The 2 most vulnerable regions for EGC have been found along the lesser curvature: the cardia in elderly patients and antrum-angularis in mid-aged and elderly patients. Most hereditary early-onset gastric carcinomas are concentrated in the corpus-fundus of young women. By histology, the most common EGC type is tubular adenocarcinoma in many growth patterns, starting in the neck of a gastric unit. Worse prognosis has been found in early papillary, compared to tubular, adenocarcinoma, related to deeper penetration, more lymphovascular invasion, and more liver and nodal metastases. Contrary to the common belief, intramucosal signet ring cell carcinoma demonstrates low risk of nodal metastasis, comparable to early intestinal-type EGC.

PRACTICAL IMPLICATIONS

The overall risk for nodal metastasis in EGC is low but significant. It is urgent to organize multicenter studies on risk of nodal metastasis in EGC in order to establish more reliable clinical practice guidelines to treat EGC patients.

Endoscopic submucosal dissection for undifferentiated-type early gastric cancer: do we have enough data to support this?

Although endoscopic submucosal dissection (ESD) is now accepted for treatment of early gastric cancers (EGC) with negligible risk of lymph node (LN) metastasis, ESD for intramucosal undifferentiated type EGC without ulceration and with diameter ≤ 2 cm is regarded as an investigational treatment according to the Japanese gastric cancer treatment guidelines. This consideration was largely based on the analysis of surgically resected EGCs that contained undifferentiated type EGCs; however, results from several institutes showed some discrepancies in sample size and incidence of LN metastasis. Recently, some reports about the safety and efficacy of ESD for undifferentiated type EGC meeting the expanded criteria have been published. Nonetheless, only limited data are available regarding long-term outcomes of ESD for EGC with undifferentiated histology so far. At the same time, endoscopists cannot ignore the patients' desire to guarantee quality of life after the relatively non-invasive endoscopic treatment when compared to conventional surgery. To satisfy the needs of patients and provide solid evidence to support ESD for undifferentiated EGC, we need more delicate tools to predict undetected LN metastasis and more data that can reveal predictive factors for LN metastasis.

A novel magnetic countertraction device for endoscopic submucosal dissection significantly reduces procedure time and minimizes technical difficulty

BACKGROUND AND STUDY AIMS

In endoscopic submucosal dissection (ESD), effective countertraction may overcome the current drawbacks of longer procedure times and increased technical demands. The objective of this study was to compare the efficacy of ESD using a novel magnetic countertraction device with that of the traditional technique.

METHODS

Each ESD was performed on simulated gastric lesions of 30 mm diameter created at five different locations. In total, 10 ESDs were performed using this novel device and 10 were performed by the standard technique.

RESULTS

The magnetic countertraction device allowed directional tissue manipulation and exposure of the submucosal space. The total procedure time was 605 ± 303.7 seconds in the countertraction group vs. 1082 ± 515.9 seconds in the control group (P = 0.021).

CONCLUSIONS

This study demonstrated that using a novel magnetic countertraction device during ESD is technically feasible and enables the operator to dynamically manipulate countertraction such that the submucosal layer is visualized directly. Use of this device significantly reduced procedure time compared with conventional ESD techniques.

Endoscopic submucosal dissection for undifferentiated-type early gastric cancer: Do we have enough data to support this?

Although endoscopic submucosal dissection (ESD) is now accepted for treatment of early gastric cancers (EGC) with negligible risk of lymph node (LN) metastasis, ESD for intramucosal undifferentiated type EGC without ulceration and with diameter ≤ 2 cm is regarded as an investigational treatment according to the Japanese gastric cancer treatment guidelines. This consideration was largely based on the analysis of surgically resected EGCs that contained undifferentiated type EGCs; however, results from several institutes showed some discrepancies in sample size and incidence of LN metastasis. Recently, some reports about the safety and efficacy of ESD for undifferentiated type EGC meeting the expanded criteria have been published. Nonetheless, only limited data are available regarding long-term outcomes of ESD for EGC with undifferentiated histology so far. At the same time, endoscopists cannot ignore the patients’ desire to guarantee quality of life after the relatively non-invasive endoscopic treatment when compared to conventional surgery. To satisfy the needs of patients and provide solid evidence to support ESD for undifferentiated EGC, we need more delicate tools to predict undetected LN metastasis and more data that can reveal predictive factors for LN metastasis.

Very well-differentiated gastric carcinoma of intestinal type: analysis of diagnostic criteria

Very well-differentiated gastric adenocarcinoma of intestinal type is a rare variant of gastric cancer characterized by low-grade nuclear atypia, and for which the diagnostic criteria and clinical behavior are not fully established. This study presents a detailed histologic, immunohistochemical, and clinical analysis of 21 cases. Nuclear atypia was mild in all cases. Characteristic architectural features of this gastric adenocarcinoma variant were pit and glandular anastomosis, spiky glands, distended glands, discohesive cells, abortive glands, and glandular outgrowth. At least three of these features were present in all the cases. Retrospective review of preoperative biopsies in 18 patients revealed that half of the biopsies were originally reported as negative or indeterminate for malignancy. On the basis of immunohistochemical stains for intestinal (MUC2, CD10, and CDX-2) and gastric (MUC5AC and MUC6) markers, 11 (52%) cases had an intestinal immunophenotype and 10 (48%) cases had a mixed immunophenotype. Foci of discohesive neoplastic cells, indicating dedifferentiation toward a poorly cohesive carcinoma, were observed exclusively in neoplasms of mixed immunophenotype (n=5). All patients with follow-up but one were alive without disease at a mean of 19 months (range 1-60 months). One individual with a pT4 tumor with associated poorly cohesive carcinoma died of disease. In summary, very well-differentiated gastric adenocarcinomas are diagnostically challenging. Architectural features are critical to making the diagnosis. Cases with pure intestinal immunophenotype have not been associated with transformation into poorly cohesive carcinoma, and appear to behave as biologically low grade. Those with mixed immunophenotype appear more likely to dedifferentiate and behave more aggressively.