Sessile Serrated Adenoma (SSA)

Epidemiology and Etiology:

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Common sites:

· Right colon

· Appendix (commonest premalignant lesion of the appendix)

Gross features:

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Histologic features:

· Serrated architecture

· Extending to base of crypts

· Villous structures maybe

· Irregularly branched crypts maybe

· Bulbous dilation of deep crypts

· lack of overt nuclear atypia (most cases)

Immunophenotype:

Marker:

Sensitivity:

Specificity:

Molecular features:

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Other features:

· May be precursor to colorectal carcinomas with high levels of microsatellite instability

References:

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