Which molecular pathway characterizes Type I (endometrioid) endometrial carcinoma?

• A TP53 mutation, HER2 amplification, and chromosomal instability
• B PTEN loss, microsatellite instability (MLH1 methylation), KRAS and CTNNB1 mutations ✓
• C ARID1A mutation leading to SWI/SNF complex loss with clear cell morphology
• D FIGO grade 3 with p53 mutation and lymphovascular invasion

Explanation

Type I endometrial carcinoma (endometrioid) arises from atypical hyperplasia in a hyperestrogenic milieu and is characterized by PTEN tumor suppressor loss (most common mutation), microsatellite instability due to MLH1 promoter hypermethylation, and KRAS and beta-catenin (CTNNB1) mutations. Type II (serous carcinoma) is characterized by TP53 mutations and chromosomal instability. These two pathways have distinct molecular, histological, and clinical profiles.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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