{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,7]],"date-time":"2026-07-07T20:14:39Z","timestamp":1783455279153,"version":"3.55.0"},"reference-count":111,"publisher":"Wiley","issue":"2","license":[{"start":{"date-parts":[[2026,4,13]],"date-time":"2026-04-13T00:00:00Z","timestamp":1776038400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"},{"start":{"date-parts":[[2026,4,13]],"date-time":"2026-04-13T00:00:00Z","timestamp":1776038400000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Histopathology"],"published-print":{"date-parts":[[2026,8]]},"abstract":"<jats:p>Loss of the myoepithelial cell (MEC) layer at the epithelial\u2013stromal interface is a key histological marker of invasion in malignant breast lesions. However, certain benign and non\u2010invasive entities may exhibit diminished or absent MECs, creating significant diagnostic challenges and occasionally leading to erroneous interpretation as invasive carcinoma. Despite their bland cytology, some of these lesions, such as microglandular adenosis (MGA) and pleomorphic adenoma, display infiltrative\u2010like growth patterns. Loss of MECs around proliferating epithelium\u2010lined clefts accompanied by spindled stroma in malignant phyllodes tumours may mimic metaplastic carcinoma. Atypical MGA lacking MECs may resemble acinic cell carcinoma. Diagnostic clues include the benign or hyperplastic appearance of the lesional cells, their immunoprofile and the absence of a sudden transition between areas with and without peripheral MECs. Awareness of such entities is key to preventing overdiagnosis and inappropriate clinical management. This review discusses these lesions, highlights their differential diagnoses and outlines key diagnostic pitfalls. Practical guidance is also provided on the optimal use and interpretation of myoepithelial markers to improve diagnostic accuracy and reduce the risk of misclassification.<\/jats:p>","DOI":"10.1111\/his.70153","type":"journal-article","created":{"date-parts":[[2026,4,14]],"date-time":"2026-04-14T01:10:19Z","timestamp":1776129019000},"page":"219-239","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Attenuated to absent myoepithelial cells in benign and non\u2010invasive breast lesions\u2014potential diagnostic pitfalls"],"prefix":"10.1111","volume":"89","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0206-7570","authenticated-orcid":false,"given":"Natthawadee","family":"Laokulrath","sequence":"first","affiliation":[{"name":"Department of Pathology, Siriraj Hospital Mahidol University  Bangkok Thailand"},{"name":"Department of Pathology and Laboratory Medicine KK Women's and Children's Hospital  Singapore Singapore"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9167-6772","authenticated-orcid":false,"given":"Hiu Yeung","family":"Lau","sequence":"additional","affiliation":[{"name":"Department of Pathology and Laboratory Medicine KK Women's and Children's Hospital  Singapore Singapore"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8078-1630","authenticated-orcid":false,"given":"Mihir","family":"Gudi","sequence":"additional","affiliation":[{"name":"Department of Pathology and Laboratory Medicine KK Women's and Children's Hospital  Singapore Singapore"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5009-5525","authenticated-orcid":false,"given":"Emad","family":"Rakha","sequence":"additional","affiliation":[{"name":"Translational Medical Science, School of Medicine The University of Nottingham and Nottingham University Hospitals NHS Trust  Nottingham UK"},{"name":"Pathology Department Hamad Medical Corporation  Doha Qatar"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1052-8605","authenticated-orcid":false,"given":"Puay Hoon","family":"Tan","sequence":"additional","affiliation":[{"name":"Department of Pathology and Laboratory Medicine KK Women's and Children's Hospital  Singapore Singapore"},{"name":"Pathology Services Luma Medical Centre  Singapore Singapore"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,4,13]]},"reference":[{"key":"e_1_2_14_2_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.mehy.2007.02.031"},{"key":"e_1_2_14_3_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.humpath.2025.105909"},{"key":"e_1_2_14_4_1","doi-asserted-by":"publisher","DOI":"10.1097\/00000478-199302000-00001"},{"key":"e_1_2_14_5_1","doi-asserted-by":"publisher","DOI":"10.1097\/00000478-198307080-00002"},{"key":"e_1_2_14_6_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2559.1983.tb02233.x"},{"key":"e_1_2_14_7_1","doi-asserted-by":"publisher","DOI":"10.1097\/00125480-199501000-00003"},{"key":"e_1_2_14_8_1","doi-asserted-by":"publisher","DOI":"10.1111\/his.12897"},{"key":"e_1_2_14_9_1","doi-asserted-by":"publisher","DOI":"10.1053\/j.semdp.2009.12.008"},{"key":"e_1_2_14_10_1","doi-asserted-by":"publisher","DOI":"10.1111\/his.12861"},{"key":"e_1_2_14_11_1","first-page":"78","volume-title":"Histology for pathologists","author":"Mills SE","year":"2019"},{"key":"e_1_2_14_12_1","doi-asserted-by":"publisher","DOI":"10.1097\/PAS.0b013e3181dd60d3"},{"key":"e_1_2_14_13_1","doi-asserted-by":"publisher","DOI":"10.1097\/01.pai.0000146545.59395.74"},{"key":"e_1_2_14_14_1","doi-asserted-by":"publisher","DOI":"10.1097\/PAS.0b013e318180431d"},{"key":"e_1_2_14_15_1","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.90.3.999"},{"key":"e_1_2_14_16_1","doi-asserted-by":"publisher","DOI":"10.1097\/00000478-200301000-00009"},{"key":"e_1_2_14_17_1","doi-asserted-by":"publisher","DOI":"10.5858\/2010-0336-CP.1"},{"key":"e_1_2_14_18_1","doi-asserted-by":"publisher","DOI":"10.1159\/000522538"},{"key":"e_1_2_14_19_1","doi-asserted-by":"publisher","DOI":"10.1097\/01.pas.0000126780.10029.f0"},{"key":"e_1_2_14_20_1","doi-asserted-by":"publisher","DOI":"10.1159\/000521682"},{"key":"e_1_2_14_21_1","doi-asserted-by":"publisher","DOI":"10.1097\/PAS.0b013e31820598a2"},{"key":"e_1_2_14_22_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2559.2007.02902.x"},{"key":"e_1_2_14_23_1","doi-asserted-by":"publisher","DOI":"10.1097\/00000478-198604000-00002"},{"key":"e_1_2_14_24_1","volume-title":"Breast tumours, WHO classification of tumours series","author":"WHO classification of Tumours Editorial Board","year":"2019"},{"key":"e_1_2_14_25_1","first-page":"209","article-title":"Hypersecretory thyroid\u2010like adenosis of the breast: a distinct benign entity devoid of myoepithelial cells","volume":"5","author":"Hung T","year":"2015","journal-title":"J Clin Exp Pathol"},{"key":"e_1_2_14_26_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.path.2012.06.007"},{"key":"e_1_2_14_27_1","doi-asserted-by":"publisher","DOI":"10.1038\/srep00226"},{"key":"e_1_2_14_28_1","doi-asserted-by":"publisher","DOI":"10.1097\/00000478-198903000-00003"},{"key":"e_1_2_14_29_1","doi-asserted-by":"publisher","DOI":"10.1111\/his.12757"},{"key":"e_1_2_14_30_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.clbc.2015.01.004"},{"key":"e_1_2_14_31_1","doi-asserted-by":"publisher","DOI":"10.1186\/bcr459"},{"key":"e_1_2_14_32_1","doi-asserted-by":"publisher","DOI":"10.1038\/ncponc0450"},{"key":"e_1_2_14_33_1","doi-asserted-by":"publisher","DOI":"10.1111\/his.13446"},{"key":"e_1_2_14_34_1","first-page":"495","article-title":"Characterization of high\u2010grade ductal carcinoma in situ with and without regressive changes: diagnostic and biologic implications","volume":"17","author":"Chivukula M","year":"2009","journal-title":"Appl. Immunohistochem. Mol. Morphol. AIMM"},{"key":"e_1_2_14_35_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ccr.2004.06.010"},{"key":"e_1_2_14_36_1","doi-asserted-by":"publisher","DOI":"10.1186\/bcr1286"},{"key":"e_1_2_14_37_1","doi-asserted-by":"publisher","DOI":"10.1387\/ijdb.113385mm"},{"key":"e_1_2_14_38_1","doi-asserted-by":"publisher","DOI":"10.1186\/bcr653"},{"key":"e_1_2_14_39_1","doi-asserted-by":"publisher","DOI":"10.1097\/PAS.0b013e31818af361"},{"key":"e_1_2_14_40_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.path.2009.02.003"},{"key":"e_1_2_14_41_1","doi-asserted-by":"publisher","DOI":"10.1136\/jclinpath-2018-205484"},{"key":"e_1_2_14_42_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00428-021-03185-4"},{"key":"e_1_2_14_43_1","doi-asserted-by":"publisher","DOI":"10.1136\/jcp.2006.040626"},{"key":"e_1_2_14_44_1","doi-asserted-by":"publisher","DOI":"10.1136\/jclinpath-2018-205485"},{"key":"e_1_2_14_45_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1600-0463.2011.02840.x"},{"key":"e_1_2_14_46_1","doi-asserted-by":"publisher","DOI":"10.1007\/978-1-4939-6697-4_5"},{"key":"e_1_2_14_47_1","doi-asserted-by":"publisher","DOI":"10.1111\/his.15101"},{"key":"e_1_2_14_48_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.humpath.2018.06.025"},{"key":"e_1_2_14_49_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1524-4741.2009.00839.x"},{"key":"e_1_2_14_50_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.prp.2004.08.006"},{"key":"e_1_2_14_51_1","doi-asserted-by":"publisher","DOI":"10.1002\/(SICI)1096-9896(199710)183:2<188::AID-PATH898>3.0.CO;2-7"},{"key":"e_1_2_14_52_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1440-1827.1991.tb03273.x"},{"key":"e_1_2_14_53_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00428-004-1181-3"},{"key":"e_1_2_14_54_1","doi-asserted-by":"publisher","DOI":"10.1097\/00000372-199712000-00003"},{"key":"e_1_2_14_55_1","doi-asserted-by":"publisher","DOI":"10.1097\/PAS.0b013e31821b3f65"},{"key":"e_1_2_14_56_1","doi-asserted-by":"publisher","DOI":"10.1111\/his.14939"},{"key":"e_1_2_14_57_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2559.2012.04207.x"},{"key":"e_1_2_14_58_1","doi-asserted-by":"publisher","DOI":"10.1177\/1066896919845493"},{"key":"e_1_2_14_59_1","doi-asserted-by":"publisher","DOI":"10.1093\/ajcp\/100.5.507"},{"key":"e_1_2_14_60_1","doi-asserted-by":"publisher","DOI":"10.1097\/PAS.0b013e31815a87e2"},{"key":"e_1_2_14_61_1","doi-asserted-by":"publisher","DOI":"10.5858\/2007-131-1397-BCAIMA"},{"key":"e_1_2_14_62_1","doi-asserted-by":"publisher","DOI":"10.1177\/106689690000800409"},{"key":"e_1_2_14_63_1","doi-asserted-by":"publisher","DOI":"10.1097\/00000478-200308000-00002"},{"key":"e_1_2_14_64_1","doi-asserted-by":"publisher","DOI":"10.1038\/modpathol.2016.161"},{"key":"e_1_2_14_65_1","doi-asserted-by":"publisher","DOI":"10.1053\/j.semdp.2022.03.001"},{"key":"e_1_2_14_66_1","doi-asserted-by":"publisher","DOI":"10.1158\/0008-5472.CAN-04-1992"},{"key":"e_1_2_14_67_1","doi-asserted-by":"publisher","DOI":"10.1038\/sj.bjc.6603483"},{"key":"e_1_2_14_68_1","doi-asserted-by":"publisher","DOI":"10.1002\/gcc.20366"},{"key":"e_1_2_14_69_1","doi-asserted-by":"publisher","DOI":"10.1093\/hmg\/11.11.1327"},{"key":"e_1_2_14_70_1","first-page":"1222","article-title":"Distinct somatic genetic changes associated with tumor progression in carriers of BRCA1 and BRCA2 germ\u2010line mutations","volume":"57","author":"Tirkkonen M","year":"1997","journal-title":"Cancer Res."},{"key":"e_1_2_14_71_1","first-page":"41","article-title":"Ductal invasive carcinoma arising within atypical microglandular adenosis in a patient with BRCA\u20101 mutation: a case report","volume":"8","author":"Ricci C","year":"2017","journal-title":"Case Rep. Perinat. Med."},{"key":"e_1_2_14_72_1","doi-asserted-by":"publisher","DOI":"10.1002\/path.4691"},{"key":"e_1_2_14_73_1","doi-asserted-by":"publisher","DOI":"10.1097\/PAP.0b013e31816ff313"},{"key":"e_1_2_14_74_1","first-page":"6149","article-title":"Carcinoma arising in microglandular adenosis of the breast: triple negative phenotype with variable morphology","volume":"7","author":"Zhong F","year":"2014","journal-title":"Int. J. Clin. Exp. Pathol."},{"key":"e_1_2_14_75_1","doi-asserted-by":"publisher","DOI":"10.1155\/2013\/736048"},{"key":"e_1_2_14_76_1","doi-asserted-by":"publisher","DOI":"10.1111\/his.14799"},{"key":"e_1_2_14_77_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.humpath.2015.12.014"},{"key":"e_1_2_14_78_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0046-8177(84)80083-0"},{"key":"e_1_2_14_79_1","doi-asserted-by":"publisher","DOI":"10.1007\/s10549-007-9569-9"},{"key":"e_1_2_14_80_1","doi-asserted-by":"publisher","DOI":"10.1046\/j.1365-2559.2000.00849.x"},{"key":"e_1_2_14_81_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.labinv.2024.102383"},{"key":"e_1_2_14_82_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.breast.2025.104501"},{"key":"e_1_2_14_83_1","doi-asserted-by":"publisher","DOI":"10.1136\/jclinpath-2012-200726"},{"key":"e_1_2_14_84_1","doi-asserted-by":"publisher","DOI":"10.1038\/modpathol.2010.82"},{"key":"e_1_2_14_85_1","doi-asserted-by":"publisher","DOI":"10.1097\/00000478-198307080-00003"},{"key":"e_1_2_14_86_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.breast.2004.04.004"},{"key":"e_1_2_14_87_1","doi-asserted-by":"publisher","DOI":"10.1111\/his.12358"},{"key":"e_1_2_14_88_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1075-122X.2004.21518.x"},{"key":"e_1_2_14_89_1","first-page":"711","article-title":"Infiltrating syringomatous adenoma of the nipple","volume":"111","author":"Slaughter MS","year":"1992","journal-title":"Surgery"},{"key":"e_1_2_14_90_1","doi-asserted-by":"publisher","DOI":"10.3346\/jkms.1987.2.4.263"},{"key":"e_1_2_14_91_1","article-title":"Syringomatous adenoma of the nipple in a male breast: a case report with a brief review of literature and Histomorphological approach to diagnosis","volume":"13","author":"Paramaguru R","year":"2021","journal-title":"Cureus."},{"key":"e_1_2_14_92_1","doi-asserted-by":"publisher","DOI":"10.29289\/2594539420240010"},{"key":"e_1_2_14_93_1","doi-asserted-by":"publisher","DOI":"10.1038\/jid.1966.24"},{"key":"e_1_2_14_94_1","doi-asserted-by":"publisher","DOI":"10.1097\/PAS.0b013e31824e0f90"},{"key":"e_1_2_14_95_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijsu.2015.05.010"},{"key":"e_1_2_14_96_1","doi-asserted-by":"publisher","DOI":"10.1111\/his.14461"},{"key":"e_1_2_14_97_1","article-title":"Pleomorphic adenoma of the breast: a rare benign lesion masquerading as a metaplastic breast carcinoma on Core\u2010needle biopsy","volume":"15","author":"Ahmad M","year":"2023","journal-title":"Cureus"},{"key":"e_1_2_14_98_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00428-004-1137-7"},{"key":"e_1_2_14_99_1","doi-asserted-by":"publisher","DOI":"10.1177\/03008916221080190"},{"key":"e_1_2_14_100_1","doi-asserted-by":"publisher","DOI":"10.12998\/wjcc.v10.i14.4648"},{"key":"e_1_2_14_101_1","doi-asserted-by":"publisher","DOI":"10.1038\/ng1596"},{"key":"e_1_2_14_102_1","unstructured":"D'AlfonsoT.College of American Pathologists: Education Pitfalls in IHC for Diagnostic Breast Pathology [Internet].2022.https:\/\/documents\u2010cloud.cap.org\/appsuite\/learning\/PiTP\/PDF\/PitfallsIHCBreastPathol.pdf."},{"key":"e_1_2_14_103_1","doi-asserted-by":"publisher","DOI":"10.3389\/fmed.2025.1673998"},{"key":"e_1_2_14_104_1","doi-asserted-by":"publisher","DOI":"10.1111\/his.15459"},{"key":"e_1_2_14_105_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1440-1827.1998.tb03929.x"},{"key":"e_1_2_14_106_1","doi-asserted-by":"publisher","DOI":"10.1097\/PAP.0b013e31814b26fe"},{"key":"e_1_2_14_107_1","doi-asserted-by":"publisher","DOI":"10.1097\/00000478-200108000-00010"},{"key":"e_1_2_14_108_1","doi-asserted-by":"publisher","DOI":"10.5858\/2003-127-0336-TRBPAP"},{"key":"e_1_2_14_109_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2559.2005.02249.x"},{"key":"e_1_2_14_110_1","doi-asserted-by":"publisher","DOI":"10.1016\/S1092-9134(99)80044-6"},{"key":"e_1_2_14_111_1","doi-asserted-by":"publisher","DOI":"10.1054\/bjoc.2001.1869"},{"key":"e_1_2_14_112_1","doi-asserted-by":"publisher","DOI":"10.1111\/his.14380"}],"container-title":["Histopathology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/his.70153","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/full-xml\/10.1111\/his.70153","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/his.70153","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,7]],"date-time":"2026-07-07T19:24:21Z","timestamp":1783452261000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/his.70153"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4,13]]},"references-count":111,"journal-issue":{"issue":"2","published-print":{"date-parts":[[2026,8]]}},"alternative-id":["10.1111\/his.70153"],"URL":"https:\/\/doi.org\/10.1111\/his.70153","archive":["Portico"],"relation":{},"ISSN":["0309-0167","1365-2559"],"issn-type":[{"value":"0309-0167","type":"print"},{"value":"1365-2559","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4,13]]},"assertion":[{"value":"2026-04-13","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}