If even the small-sized focus of cancer involvement in gastritis cystica is found in the early stage, it is likely that they have the potential to invade and metastasize to the other organ much earlier than the potentially malignant cells located in the mucosa. The molecular interest is that how precursor cells or cancer cells within the muscularis mucosa undergo the different "evolution" to acquire the invasive phenotype as compared with the typical ones. 

Dear Yosep,

I assume that the specimen is a gastric stump after partial gastrectomy and that there are aspects of "gastritis cystica profunda" not associated with dysplastic changes. It seems to me quite strange that there are no gastric glands in the absence of a major fibrosis. With the limitations due to see a picture, to differences in interpretation of these lesions in West and East (where the gradation of the lesion is usually more severe) and finally to the objective difficulty (or impossibility) to distinguish intramucosal adenocarcinoma and severe diplasia, it seems to me that the intramucosal lesion could be interpreted as a severe dysplasia / adenocarcinoma in situ. If the above is true, the involvement of "gastritis cystica profunda" from cancer should not be a clinical-stage problem. As a rule, the infiltration of the submucosa is associated with desmoplasia, although it is not always true, especially in infiltrating carcinomas with bland appearance and large cyst-like glands.   Finally I do not answer to your question, except that a decision can only be taken by the assessment of the whole case.

Anyway congratulations for what you have proposed.

For me it is a pleasure to remember that the term "gastritis cystica profunda" was proposed by two  my dear friends and teachers.

http://www.ncbi.nlm.nih.gov/pubmed/7286916

I was also worrying about the question you have raised after i took this picture by my cell phone, that some researchers would think this is not a cancer but dysplasia or adenoma or something. It was a very well defined lesion with more definite portion of cancer and the picture is somewhat less representative. I don't want to argue about the difference of western and eastern criteria when diagnosing  gastric cancers here but just want to hear about the opinions on the  T stage of this kind of situation where gastritis cystica profunda is associated. 

Thank you for your kind answers anyway though. 

The photo provided looks like a T1b.  

If your concern is that this may lead to overtreatment of your patient, than it may be worth mentioning in your report or directly that that the presence of gastritis cystica profunda is present and may be affecting the assessment of T-stage of the tumor.  

Dear Yosep,

this is an interesting case but I'm not sure your question can be answered reliably by just looking at the photomicrographs provided. Ideally, I would like to see the slide under the microscop myself.

Nevertheless, here are some thoughts.

I'm not sure this is gastritis cystica profunda. To me the deep seated cystic glands look like being part of the neoplastic process. Or is there evidence of gastric cystica profunda not involved by the neoplastic process elsewhere?

Did you do immunostains for Ki-67 or p53?

In any case, distinguishing between G.c.p. and well differentiated adenocarcinoma can be extremely difficult (see paper by Godman Greywoode published in the American Journal of Surgical Pathology in 2011 and subsequent letter by Ozde and colleagues in 2012).

Finally, as always with the TNM system: if in doubt, downstage.

Hope this is helpful

Dear Gerald,

Thank you for your thoughtful answer.

My colleagues and I found several other lesions with bland epithelium, which can be clearly classified as GCP. This lead clinicians to get an impression of advanced cancer on endoscopy. I also agree that differential diagnosis of GCP and invasion of extremely well differentiated adenocarcinoma can be very difficult. But my colleagues and I agree that this is glandular involvement of adenocarcinoma morphologically because the lining epithelium showed evident cytological atypia and Ki-67 labeling index of the cells of these epithelium and the tumor cells were similarly high. (I also agree that this photograph does not represent the whole tumor very clearly because those were taken by my cellphone camera through the eyepiece of the microscope)

I just wanted to emphasize that there can be several situations like this in which subjective opinions of pathologists can infer the pathologic reports, and if there is reliable consensus or opinions for solving this problem. If there is a relavant rationale for why do so, it will be even better.

Will there be some specific reasons for you to choose to downstage in this case?