Mismatch repair protein deficiency is common in sebaceous neoplasms and suggests the importance of screening for Lynch syndrome.
The association between Lynch syndrome and sebaceous neoplasms is well characterized. The absence of expression of mismatch repair proteins (MMRPs) by immunohistochemistry (IHC) is often used in other Lynch-associated tumors to guide testing. IHC for MLH1, PMS2, MSH2, and MSH6 was performed on 36 benign and malignant sebaceous neoplasms with the absence of one or more MMRP in 38.9% of cases. Among lesions with abnormal IHC, 71.4% were missing both MSH2 and MSH6, 21.4% lacked MLH1 and PMS2, and 7.1% lacked only MSH6. Of the 10 patients with absent MMRP, 5 had gene-test confirmed Lynch syndrome, 3 had no suggestive personal or family medical history and 2 had no recorded data. Tumor-infiltrating lymphocytes in neoplasms with absent MMRP were statistically significantly greater than in those with intact MMRP (16.5 vs. 9.7, P = 0.027). MMRP deficiency is common in sebaceous neoplasms, suggesting the importance of screening for Lynch syndrome in these patients.
Department of Pathology, The Wexner Medical Center at The Ohio State University, Columbus, OH, USA.
Elizabeth F
EF
Plocharczyk
Wendy L
WL
Frankel
Heather
H
Hampel
Sara B
SB
Peters
D048868:Adaptor Proteins, Signal Transducing / Q000172:deficiency; D000251:Adenosine Triphosphatases / Q000172:deficiency; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000235:genetics / Q000378:metabolism*; D004260:DNA Repair; D045643:DNA Repair Enzymes / Q000172:deficiency; D004268:DNA-Binding Proteins / Q000172:deficiency; D006801:Humans; D007150:Immunohistochemistry; D000070976:Mismatch Repair Endonuclease PMS2; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein / Q000172:deficiency; D009378:Neoplasms, Multiple Primary / Q000378:metabolism*; D009687:Nuclear Proteins / Q000172:deficiency; D012626:Sebaceous Gland Neoplasms / Q000235:genetics / Q000378:metabolism*
D048868:Adaptor Proteins, Signal Transducing; D004268:DNA-Binding Proteins; C094443:G-T mismatch-binding protein; C501486:MLH1 protein, human; D009687:Nuclear Proteins; D000251:Adenosine Triphosphatases; C094934:PMS2 protein, human; C497172:MSH2 protein, human; D000070976:Mismatch Repair Endonuclease PMS2; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein; D045643:DNA Repair Enzymes