This interactive tool features CLDN18-stained slides selected by a committee of experts. It allows you to explore a gallery of cases with matched, whole slide images. You can also sharpen your interpretive skills with a self-guided quiz, which compares your answers with those of our committee of experts.
- Explore our stain gallery
- Stain interpretation quiz
Use this virtual microscope to explore a gallery of CLDN18-stained cases.
Use the criteria below to refine the cases and click on the cases below to perform virtual microscopy.
API Error while loading stain gallery learning section
LOAD MORE CASES
Test your knowledge on CLDN18 stain interpretation
Click on the cases below to test your stain interpretation skills
Please select any one option before you submit
API Error while loading stain gallery training section
LOAD MORE CASES
What is the percentage of tumour cells stained with moderate-to-strong (2+/3+) membranous stain intensity?
Please select any one option before you submit
Correct!
Your response is consistent with the consensus scoring. The consensus score is 5% moderate-to-strong membranous stain intensity.
Only ~5% of the tumor cells show strong-to-moderate membranous staining intensity, with the remainder of tumor cells showing no-to-low staining intensity.
Watch the adjacent video for more information about this case.
Incorrect.
Your response is inconsistent with the consensus scoring. The consensus score is 5% moderate-to-strong membranous stain intensity.
Only ~5% of the tumor cells show strong-to-moderate membranous staining intensity, with the remainder of tumor cells showing no-to-low staining intensity.
Watch the adjacent video for more information about this case.
What is the percentage of tumour cells stained with moderate-to-strong (2+/3+) membranous stain intensity?
Please select any one option before you submit
Correct!
Your response is consistent with the consensus scoring. The consensus score is 5% moderate-to-strong membranous stain intensity.
There is strong staining observed in normal foveolar epithelial cells and normal/dysplastic superficial mucosa and heterogeneous staining of the tumor area, with strong-to-moderate membranous expression localized to only one area in the middle of the tumor.
Watch the adjacent video for more information about this case.
Incorrect.
Your response is inconsistent with the consensus scoring. The consensus score is 5% moderate-to-strong membranous stain intensity.
There is strong staining observed in normal foveolar epithelial cells and normal/dysplastic superficial mucosa and heterogeneous staining of the tumor area, with strong-to-moderate membranous expression localized to only one area in the middle of the tumor.
Watch the adjacent video for more information about this case.
What is the percentage of tumour cells stained with moderate-to-strong (2+/3+) membranous stain intensity?
Please select any one option before you submit
Correct!
Your response is consistent with the consensus scoring. The consensus score is 0% moderate-to-strong membranous stain intensity.
The non-neoplastic gastric glands exhibit moderate-to-strong expression; however, tumor cells are completely negative for CLDN18.2.
Incorrect.
Your response is inconsistent with the consensus scoring. The consensus score is 0% moderate-to-strong membranous stain intensity.
The non-neoplastic gastric glands exhibit moderate-to-strong expression; however, tumor cells are completely negative for CLDN18.2.
What is the percentage of tumour cells stained with moderate-to-strong (2+/3+) membranous stain intensity?
Please select any one option before you submit
Correct!
Your response is consistent with the consensus scoring. The consensus score is 90% moderate-to-strong membranous stain intensity.
There is intense staining of the foveolar epithelium at the surface and normal mucosa, specific membranous staining that is strong-to-moderate in ~90% of the signet ring-type gastric carcinoma in the mucosa/submucosa, with some weak staining at the invasive front.
Watch the adjacent video for more information about this case.
Incorrect.
Your response is inconsistent with the consensus scoring. The consensus score is 90% moderate-to-strong membranous stain intensity.
There is intense staining of the foveolar epithelium at the surface and normal mucosa, specific membranous staining that is strong-to-moderate in ~90% of the signet ring-type gastric carcinoma in the mucosa/submucosa, with some weak staining at the invasive front.
Watch the adjacent video for more information about this case.
What is the percentage of tumour cells stained with moderate-to-strong (2+/3+) membranous stain intensity?
Please select any one option before you submit
Correct!
Your response is consistent with the consensus scoring. The consensus score is 85% moderate-to-strong membranous stain intensity.
This is a moderately differentiated adenocarcinoma with epithelial structure that exhibits strong membranous staining in most of the tumor cells, which can be observed even at lower magnification.
Watch the adjacent video for more information about this case.
Incorrect.
Your response is inconsistent with the consensus scoring. The consensus score is 85% moderate-to-strong membranous stain intensity.
This is a moderately differentiated adenocarcinoma with epithelial structure that exhibits strong membranous staining in most of the tumor cells, which can be observed even at lower magnification.
Watch the adjacent video for more information about this case.
What is the percentage of tumour cells stained with moderate-to-strong (2+/3+) membranous stain intensity?
Please select any one option before you submit
Correct!
Your response is consistent with the consensus scoring. The consensus score is 35% moderate-to-strong membranous stain intensity.
The left side of the sample is negative for CLDN18 staining, but there is some moderate-to-strong staining in the tumor cells in the right side of the sample, assessed as ~35% positive; any artifact and/or background staining should not be assessed.
Watch the adjacent video for more information about this case.
Incorrect.
Your response is inconsistent with the consensus scoring. The consensus score is 35% moderate-to-strong membranous stain intensity.
The left side of the sample is negative for CLDN18 staining, but there is some moderate-to-strong staining in the tumor cells in the right side of the sample, assessed as ~35% positive; any artifact and/or background staining should not be assessed.
Watch the adjacent video for more information about this case.
What is the percentage of tumour cells stained with moderate-to-strong (2+/3+) membranous stain intensity?
Please select any one option before you submit
Correct!
Your response is consistent with the consensus scoring. The consensus score is 5% moderate-to-strong membranous stain intensity.
This is a purely cohesive adenocarcinoma with some mucin production, the presence of some signet ring cells,and tumor cells in the sclerotic area and within the stroma; CLDN18 staining is absent throughout.
Watch the adjacent video for more information about this case.
Incorrect.
Your response is inconsistent with the consensus scoring. The consensus score is 5% moderate-to-strong membranous stain intensity.
This is a purely cohesive adenocarcinoma with some mucin production, the presence of some signet ring cells,and tumor cells in the sclerotic area and within the stroma; CLDN18 staining is absent throughout.
Watch the adjacent video for more information about this case.
What is the percentage of tumour cells stained with moderate-to-strong (2+/3+) membranous stain intensity?
Please select any one option before you submit
Correct!
Your response is consistent with the consensus scoring. The consensus score is 0% moderate-to-strong membranous stain intensity.
This is a high-grade adenocarcinoma infiltrating the gastric wall with retained non-neoplastic mucosa exhibiting strong 3+ CLDN18 staining; all neoplastic cells are completely negative. In this case, the presence of normal gastric mucosa serves as an internal positive control.
Watch the adjacent video for more information about this case.
Incorrect.
Your response is inconsistent with the consensus scoring. The consensus score is 0% moderate-to-strong membranous stain intensity.
This is a high-grade adenocarcinoma infiltrating the gastric wall with retained non-neoplastic mucosa exhibiting strong 3+ CLDN18 staining; all neoplastic cells are completely negative. In this case, the presence of normal gastric mucosa serves as an internal positive control.
Watch the adjacent video for more information about this case.
What is the percentage of tumour cells stained with moderate-to-strong (2+/3+) membranous stain intensity?
Please select any one option before you submit
Correct!
Your response is consistent with the consensus scoring. The consensus score is 60% moderate-to-strong membranous stain intensity.
This is an infiltrating adenocarcinoma with glandular neoplastic epithelium throughout; it is heterogeneous, exhibiting strong membranous CLDN18 staining in ~60% of neoplastic cells, with areas of weak-to-moderate expression as well as areas completely absent of CLDN18.
Watch the adjacent video for more information about this case.
Incorrect.
Your response is inconsistent with the consensus scoring. The consensus score is 60% moderate-to-strong membranous stain intensity.
This is an infiltrating adenocarcinoma with glandular neoplastic epithelium throughout; it is heterogeneous, exhibiting strong membranous CLDN18 staining in ~60% of neoplastic cells, with areas of weak-to-moderate expression as well as areas completely absent of CLDN18.
Watch the adjacent video for more information about this case.
What is the percentage of tumour cells stained with moderate-to-strong (2+/3+) membranous stain intensity?
Please select any one option before you submit
Correct!
Your response is consistent with the consensus scoring. The consensus score is 85% moderate-to-strong membranous stain intensity.
There is very strong expression in the normal mucosa, which is not included in scoring; ~85% of the adjacent neoplastic cells exhibit moderate stain intensity with some areas of intense staining.
Watch the adjacent video for more information about this case.
Incorrect.
Your response is inconsistent with the consensus scoring. The consensus score is 85% moderate-to-strong membranous stain intensity.
There is very strong expression in the normal mucosa, which is not included in scoring; ~85% of the adjacent neoplastic cells exhibit moderate stain intensity with some areas of intense staining.
Watch the adjacent video for more information about this case.
What is the percentage of tumour cells stained with moderate-to-strong (2+/3+) membranous stain intensity?
Please select any one option before you submit
Correct!
Your response is consistent with the consensus scoring. The consensus score is 100% moderate-to-strong membranous stain intensity.
Both the tumor tissue and normal mucosa show strong, primarily membranous staining, with some cytoplasmic staining. In this case, the non-neoplastic mucosa serves as an internal positive control and intestinal metaplasia serves as negative control.
Watch the adjacent video for more information about this case.
Incorrect.
Your response is inconsistent with the consensus scoring. The consensus score is 100% moderate-to-strong membranous stain intensity.
Both the tumor tissue and normal mucosa show strong, primarily membranous staining, with some cytoplasmic staining. In this case, the non-neoplastic mucosa serves as an internal positive control and intestinal metaplasia serves as negative control.
Watch the adjacent video for more information about this case.
What is the percentage of tumour cells stained with moderate-to-strong (2+/3+) membranous stain intensity?
Please select any one option before you submit
Correct!
Your response is consistent with the consensus scoring. The consensus score is 85% moderate-to-strong membranous stain intensity.
This is a tubulo-papillary gastric adenocarcinoma with diffuse moderate-to-strong CLDN18 staining. There is limited intratumoral heterogeneity with small sections of little-to-no expression, and the majority of tumor cells exhibiting 2+ or 3+ intensity.
Watch the adjacent video for more information about this case.
Incorrect.
Your response is inconsistent with the consensus scoring. The consensus score is 85% moderate-to-strong membranous stain intensity.
This is a tubulo-papillary gastric adenocarcinoma with diffuse moderate-to-strong CLDN18 staining. There is limited intratumoral heterogeneity with small sections of little-to-no expression, and the majority of tumor cells exhibiting 2+ or 3+ intensity.
Watch the adjacent video for more information about this case.
What is the percentage of tumour cells stained with moderate-to-strong (2+/3+) membranous stain intensity?
Please select any one option before you submit
Correct!
Your response is consistent with the consensus scoring. The consensus score is 30% moderate-to-strong membranous stain intensity.
In the intramucosal region ~50% of tumor cells exhibit moderate-to-strong stain intensity, with staining almost absent in the deeper lesion; assessed overall as ~30% of all tumor cells with moderate-to-strong intensity.
Watch the adjacent video for more information about this case.
Incorrect.
Your response is inconsistent with the consensus scoring. The consensus score is 30% moderate-to-strong membranous stain intensity.
In the intramucosal region ~50% of tumor cells exhibit moderate-to-strong stain intensity, with staining almost absent in the deeper lesion; assessed overall as ~30% of all tumor cells with moderate-to-strong intensity.
Watch the adjacent video for more information about this case.
What is the percentage of tumour cells stained with moderate-to-strong (2+/3+) membranous stain intensity?
Please select any one option before you submit
Correct!
Your response is consistent with the consensus scoring. The consensus score is 70% moderate-to-strong membranous stain intensity.
This is an intestinal-type, medium-grade invasive gastric carcinoma with intensely stained normal mucosa at the surface, and very heterogeneous staining within the tumor; overall approximately two thirds of the tumor cells exhibit moderate-to-strong staining.
Watch the adjacent video for more information about this case.
Incorrect.
Your response is inconsistent with the consensus scoring. The consensus score is 70% moderate-to-strong membranous stain intensity.
This is an intestinal-type, medium-grade invasive gastric carcinoma with intensely stained normal mucosa at the surface, and very heterogeneous staining within the tumor; overall approximately two thirds of the tumor cells exhibit moderate-to-strong staining.
Watch the adjacent video for more information about this case.
What is the percentage of tumour cells stained with moderate-to-strong (2+/3+) membranous stain intensity?
Please select any one option before you submit
Correct!
Your response is consistent with the consensus scoring. The consensus score is 65% moderate-to-strong membranous stain intensity.
This case includes two different endoscopy biopsies from the same adenocarcinoma; one is differentiated and completely negative for CLDN18, while the other is a high-grade adenocarcinoma with some negative areas, but mostly strong, diffuse staining scored as 3+.
Watch the adjacent video for more information about this case.
Incorrect.
Your response is inconsistent with the consensus scoring. The consensus score is 65% moderate-to-strong membranous stain intensity.
This case includes two different endoscopy biopsies from the same adenocarcinoma; one is differentiated and completely negative for CLDN18, while the other is a high-grade adenocarcinoma with some negative areas, but mostly strong, diffuse staining scored as 3+.
Watch the adjacent video for more information about this case.