Isolated MSH2 Loss With Divergent Microsatellite Instability Status in Colorectal and Prostate Adenocarcinoma: A Diagnostic Pitfall.
BackgroundThe fidelity of the DNA mismatch repair (MMR) system is routinely evaluated using MMR immunohistochemistry (IHC). The MMR IHC is interpreted based on obligate heterodimeric relationships (MLH1-PMS2; MSH2-MSH6). MSH2 loss typically results in concurrent MSH6 loss. Atypical non-dimer patterns, such as isolated...