APPENDICURE

A new study put a number on a real problem with goblet cell adenocarcinoma grading. Even expert pathologists often disagree on the grade. When seven of them looked at the same slides, they all landed on the same grade in only four out of twenty cases.

What the study found about goblet cell adenocarcinoma grading

The study came out in June 2026 in the journal Histopathology. The researchers took 58 scanned slides from 20 goblet cell adenocarcinoma cases and sent them to seven pathologists who focus on appendix tissue. Each one graded the cases with the current method, the three-tier grade from the World Health Organization’s 5th edition. Then they measured how often the pathologists agreed.

The agreement was rated fair, which is a weak result. All seven matched on the grade in four of the twenty cases. On the rest, at least one pathologist read it differently. They lined up better on some features, like the amount of mucin, and worse on others, like whether there was tissue death, called necrosis.

This doesn’t mean your pathology report is wrong. In many cases, the diagnosis is straightforward. The challenge is that some goblet cell adenocarcinomas have features that fall between grades, and that’s where experienced pathologists may reasonably disagree.

Why the grade matters

Grade is one of several things your care team considers when discussing prognosis and treatment. It helps provide context alongside the stage, where the cancer has spread, imaging, pathology, and your overall clinical picture. It isn’t just a word in the pathology report. It can influence how your doctors think about your cancer and talk with you about it. So when goblet cell adenocarcinoma grading is this hard to pin down, that uncertainty can become part of the discussion when doctors interpret the pathology alongside everything else they know about your case.

What goblet cell adenocarcinoma is

Goblet cell adenocarcinoma is a specific subtype of appendix cancer. It used to be called goblet cell carcinoid, but the World Health Organization changed the name in 2019 to reflect that it behaves like a true adenocarcinoma. I wrote a full explainer on that name change if you want the background. You can also see where it sits among the other subtypes on the Types of Appendix Cancer page.

A simpler grade the authors suggest

The researchers behind this study think the current three-tier grade may be asking too much. They point to a simpler two-tier system, low grade or high grade, that earlier work found easier for pathologists to agree on.

I want to be careful here. This is a proposal from the researchers, not a new standard, and nothing about how your own grade was assigned has changed. The point of the study isn’t to replace the current grading system. It’s to show that even experienced pathologists don’t always interpret these tumors the same way.

What this means for you

If your diagnosis is goblet cell adenocarcinoma and the grade is driving a big decision, it is reasonable to ask for a second read from a pathologist at a high-volume center that sees a lot of appendix cancer. A second opinion is not a sign that anyone did anything wrong. It is a normal step when the reading is genuinely hard, and this study shows it often is. It is also fair to ask your own team how confident they are in the grade, and whether your case is a clear one or a close call. If this diagnosis is new to you, I also put together a guide for that first stretch.

I am the founder of Appendicure and a caregiver, not a physician. Nothing here is medical advice. Every decision about your diagnosis and treatment should be made with your own care team, who know your case.

Sources and further reading

Marins LV, Murden R, Misdraji J, et al. High interobserver variability exists in grading appendiceal goblet cell adenocarcinoma using World Health Organization 5th edition criteria. Histopathology. 2026. doi:10.1111/his.70205