{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,20]],"date-time":"2026-09-20T14:04:14Z","timestamp":1789913054520,"version":"4.0.1"},"reference-count":29,"publisher":"SAGE Publications","license":[{"start":{"date-parts":[[2026,9,18]],"date-time":"2026-09-18T00:00:00Z","timestamp":1789689600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"},{"start":{"date-parts":[[2026,9,18]],"date-time":"2026-09-18T00:00:00Z","timestamp":1789689600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["Int J Surg Pathol"],"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>The 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 loss of MSH2 with retained or patchy MSH6, complicate reflex testing and genotype inference.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Patient presentation<\/jats:title>\n                    <jats:p>\n                      Patient 1 was a 90-year-old woman with an ascending colon mass. Biopsy showed invasive moderately differentiated colorectal adenocarcinoma. MMR IHC demonstrated isolated loss of MSH2 with heterogeneous\/patchy MSH6 retention. Polymerase chain reaction (PCR)-based microsatellite instability (MSI) testing was reported as microsatellite stable (MSS). Targeted testing showed no\n                      <jats:italic toggle=\"yes\">KRAS<\/jats:italic>\n                      \/\n                      <jats:italic toggle=\"yes\">NRAS<\/jats:italic>\n                      or\n                      <jats:italic toggle=\"yes\">BRAF V600E<\/jats:italic>\n                      mutations. Patient 2 was a 70-year-old man with recurrent high-grade prostatic carcinoma sampled by transurethral resection of the prostate (TURP) from the pelvic bed. MMR IHC demonstrated intact MLH1\/PMS2\/MSH6 with isolated loss of nuclear MSH2, accompanied by very faint cytoplasmic staining. These IHC findings were reproduced on an additional block. MSI testing was reported as MSI-High (MSI-H).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>A focused literature review identified this non-dimeric pattern of isolated MSH2 loss across multiple tumor types, most commonly colorectal, prostate, and endometrial carcinomas. Our paired findings illustrate that this non-dimeric pattern may coexist with either MSS or MSI-H status, underscoring that MMR IHC patterns should be confirmed for repeatability and interpreted in the context of clinicopathologic and molecular correlation.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1177\/10668969261478659","type":"journal-article","created":{"date-parts":[[2026,9,18]],"date-time":"2026-09-18T13:44:18Z","timestamp":1789739058000},"update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":0,"title":["Isolated MSH2 Loss With Divergent Microsatellite Instability Status in Colorectal and Prostate Adenocarcinoma: A Diagnostic Pitfall"],"prefix":"10.1177","author":[{"given":"Pramath","family":"Kakodkar","sequence":"first","affiliation":[{"name":"University of Saskatchewan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0006-1730-4870","authenticated-orcid":false,"given":"Hui","family":"Wang","sequence":"additional","affiliation":[{"name":"University of Saskatchewan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"179","published-online":{"date-parts":[[2026,9,18]]},"reference":[{"key":"e_1_3_2_2_2","doi-asserted-by":"publisher","DOI":"10.1159\/000531003"},{"key":"e_1_3_2_3_2","doi-asserted-by":"publisher","DOI":"10.1002\/cncr.35030"},{"key":"e_1_3_2_4_2","doi-asserted-by":"publisher","DOI":"10.1200\/PO.23.00648"},{"key":"e_1_3_2_5_2","doi-asserted-by":"publisher","DOI":"10.1200\/PO.22.00525"},{"key":"e_1_3_2_6_2","doi-asserted-by":"publisher","DOI":"10.1038\/nm.4191"},{"key":"e_1_3_2_7_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa043146"},{"key":"e_1_3_2_8_2","doi-asserted-by":"publisher","DOI":"10.1200\/PO.17.00084"},{"key":"e_1_3_2_9_2","doi-asserted-by":"publisher","DOI":"10.1038\/nature13480"},{"key":"e_1_3_2_10_2","doi-asserted-by":"publisher","DOI":"10.1186\/s13045-021-01166-3"},{"key":"e_1_3_2_11_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.pharmthera.2018.04.004"},{"key":"e_1_3_2_12_2","doi-asserted-by":"publisher","DOI":"10.1038\/nrm1907"},{"key":"e_1_3_2_13_2","doi-asserted-by":"publisher","DOI":"10.1038\/371075a0"},{"key":"e_1_3_2_14_2","doi-asserted-by":"publisher","DOI":"10.1158\/1078-0432.CCR-08-3012"},{"key":"e_1_3_2_15_2","doi-asserted-by":"publisher","DOI":"10.7554\/eLife.49138"},{"key":"e_1_3_2_16_2","doi-asserted-by":"publisher","DOI":"10.3389\/fonc.2022.1019798"},{"key":"e_1_3_2_17_2","doi-asserted-by":"publisher","DOI":"10.1097\/PAS.0000000000000663"},{"key":"e_1_3_2_18_2","doi-asserted-by":"publisher","DOI":"10.3389\/fonc.2023.1069467"},{"key":"e_1_3_2_19_2","doi-asserted-by":"publisher","DOI":"10.1002\/cjp2.120"},{"key":"e_1_3_2_20_2","doi-asserted-by":"publisher","DOI":"10.1007\/s00428-023-03661-z"},{"key":"e_1_3_2_21_2","doi-asserted-by":"publisher","DOI":"10.3390\/cancers11101567"},{"key":"e_1_3_2_22_2","doi-asserted-by":"publisher","DOI":"10.1093\/jnci\/djh034"},{"key":"e_1_3_2_23_2","doi-asserted-by":"publisher","DOI":"10.1155\/2004\/136734"},{"key":"e_1_3_2_24_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41379-018-0058-y"},{"key":"e_1_3_2_25_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41379-021-00918-3"},{"key":"e_1_3_2_26_2","doi-asserted-by":"publisher","DOI":"10.1186\/s13000-024-01447-8"},{"issue":"3","key":"e_1_3_2_27_2","first-page":"164","article-title":"Characterization of molecular alterations in an unusual case of Lynch syndrome\u2013associated adrenocortical carcinoma","volume":"22","author":"Parilla M","year":"2017","unstructured":"Parilla M, Furtado LV, Kadri S, Segal J, Antic T. 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