Review for 10.1186/s12876-020-01238-7 (2020)

Reviewer’s report
Title: Juvenile polyposis syndrome might be misdiagnosed as familial adenomatous polyposis: a
case report and literature review
Version: 0 Date: 14 Jan 2020
Reviewer: Warren Hyer
Reviewer's report:
Thank you for submitting the case report. 
Starting  with  the  42  year  old,  the  reality  is  this  man  was  misdiagnosed  with  FAP despite  the
colonoscopic appearances at diagnosis to be more typical of JPS. teh uathors acknowledge this was a
misdiagnosis  The decision for colectomy was probably based on the prescence of the cancer - and
whether this was FAP or JPS might not have changed his management at the time - if he did indeed
have FAP he would also have been referred for duodenal surveillancev etc. The colonoscopist who
performed the pre operative colonoscopy and the pathologist who looked at the sample would have
been able to see that the appearance macroscopically was not typical of FAP and this alone would have
directed the clinician to the correct diagnosis. Therefore fundamentally, it was not ideal that the 42 year
old was provided with the diagnosis of FAP. This frames my opinion of this case report.
The case report is valid in highlighting the presence of dysplasia in JPS large hamaratomas, as quoted
correctly in the reference (8.5%). This case report is an honest reflection by the authors that the
colonoscopist and histopathologist were misdirected to a diagnosis of FAP by the presence of dysplasia.
The authors are honest that this was a misdiagnosis. 
My advice for the authors is that they should stress that the diagnosis of JPS versus FAP, is based on
clinical presentation, endoscopic appearance, genetic investigations and not judged on the presence or
abscence of dysplasia in the polyps. Perhaps a table listing the differences in each of these issues would
be helpful, stressing why dysplasia alone cannot be used to discern if this is FAP. This might support
the text in the discussion
The paragraph about about Cowden and PJS is unnecessary and somewhat confusing when discussing
JPS with a BMPR1A mutation.
Overall, I think this case report is helpful - it is an honest reflection on how FAP can be misdiagnosed
using histopathology alone and not taking into account the endoscopic appearance of the polyps,
genetic investigations. For that reason it is worth publication taking into account the comments above.
Are the methods appropriate and well described?
If not, please specify what is required in your comments to the authors.
Yes
Does the work include the necessary controls?
If not, please specify which controls are required in your comments to the authors.
Yes
Are the conclusions drawn adequately supported by the data shown?
If not, please explain in your comments to the authors.
Yes
Are you able to assess any statistics in the manuscript or would you recommend an
additional statistical review?
If an additional statistical review is recommended, please specify what aspects require further
assessment in your comments to the editors.
Not relevant to this manuscript
Quality of written English
Please indicate the quality of language in the manuscript:
Acceptable
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