Colorectal polyposes: from phenotype to diagnosis

Area of Science:

• Gastroenterology and Pathology
• Clinical Genetics and Hereditary Syndromes

Background:

• Colorectal polyposis syndromes are uncommon and pose diagnostic challenges.
• Germline mutation demonstration is the definitive diagnostic method but not always feasible.
• Some polyposis forms lack a known genetic basis, emphasizing phenotypic description.

Purpose of the Study:

• To review the principles and challenges in comprehensively describing colorectal polyposis phenotypes.
• To guide pathologists in accurate phenotypic assessment for working diagnoses.
• To aid in identifying underlying genetic causes and assessing colorectal cancer risk.

Main Methods:

• Review of diagnostic principles and pitfalls in colorectal polyposis.
• Focus on pathological description of various polyposis types.
• Discussion of challenges including sample limitations and polyp heterogeneity.

Main Results:

• Accurate pathological phenotype description is central to diagnosing colorectal polyposis.
• Diagnostic challenges arise from polyp number, size, gross recognition, and histological classification.
• Review covers classical FAP, attenuated FAP, MAP, P-JS, JPS, CS, HMPS, and HPS.

Conclusions:

• Comprehensive pathological description is essential for accurate colorectal polyposis diagnosis and management.
• Understanding phenotypic variations aids in directing genetic testing and risk stratification.
• This review highlights key considerations for pathologists managing colorectal polyposis cases.