Excerpt
Methods: Quantitative beta catenin expression and intracellular distribution was studied by immunohistochemistry. We compared 41 polyps from 7 patients (4M) with Juvenile Polyposis Syndrome with 17 polyps from 17 patients (11M) with isolated juvenile polyps, a negative family history of hereditary polyposis syndrome, and no history of recurrence based on questionnaire or repeat endoscopy at 5–10 years following initial presentation. Beta catenin staining was classified as nuclear stippling, cytoplasmic localization and intensity of staining.
Results: Basal cytoplasmic localization of beta catenin was observed more frequently in sporadic than syndromic polyps (31 vs 17%) and nuclear stippling pattern was reported more often with syndromic polyps (87 vs 75% NS). Although the intensity of cytoplasmic staining was almost identical, 2 syndromic polyps exhibited markedly increased cytoplasmic staining.
Conclusion: Our findings do not support the use of beta catenin immunohistochemistry in differentiating between syndromic and sporadic JP: indeed beta catenin over-expression and nuclear translocation may have a role in the growth of a subset of JPS associated polyps; this phenotypic diversity may be related to the genetic heterogeneity of JPS.