Nguyen CV, et al. - Researchers examined whether different sebaceous neoplasms (SNs) in patients with known Muir-Torre syndrome (MTS) exhibit concordance in mismatch repair protein (MMRP) immunohistochemical (IHC) staining pattern. They conducted retrospective assessment of single-center case series of 11 patients with MTS evaluating 38 SNs in these patients for MMRP IHC staining patterns. High intrapatient concordance of MMRP IHC staining was observed between different sebaceous neoplasms of individual patients (range, 2-4 lesions per patient); 36 of 38 lesions matched the confirmed germline mutation (sensitivity, 94.7%; 95% CI, 82.3%-99.4%). In all patients, extrafacial lesions (n = 16) corresponded to patients’ known germline mutation. Findings thereby indicate high reproducibility of MMRP IHC across sebaceous lesions within an individual patient with MTS, and a possible utility of this test to support a diagnosis of MTS when clinical suspicion is strong.