{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T09:21:01Z","timestamp":1787649661173,"version":"build-2736575974"},"reference-count":23,"publisher":"SAGE Publications","license":[{"start":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T00:00:00Z","timestamp":1785888000000},"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>Primary squamous cell carcinoma of the breast is an extremely rare subtype of metaplastic breast carcinoma, often showing aggressive clinical behavior and posing diagnostic challenges, particularly when acantholysis is present and mimics vascular neoplasms.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Patient presentation<\/jats:title>\n                    <jats:p>We report a 49-year-old woman presenting with a rapidly growing palpable mass in the outer quadrant of the left breast. Initial cytology yielded keratin debris interpreted as benign. Following inflammatory changes, the lesion was excised with a clinical pre-diagnosis of granulomatous mastitis. Gross examination revealed an 8\u2009\u00d7\u20097\u2009\u00d7\u20097 cm partial mastectomy specimen containing a 6\u2009\u00d7\u20095\u2009\u00d7\u20094 cm firm, cystically and hemorrhagically degenerated, irregularly circumscribed tumor adjacent to but not continuous with the overlying skin. Microscopically, the tumor consisted of infiltrating nests of squamous epithelial cells with widespread acantholysis and single-cell keratinization, moderate nuclear atypia, and absence of lymphovascular or perineural invasion. Associated ductal carcinoma in situ was identified. Immunohistochemically, the tumor cells expressed pan-keratin, keratin 5\/6, keratin 14, p63, CD10 (MME), and EGFR, while ER, PR, HER2, and GATA3 were negative. Ki-67 (MKI67) proliferation index was approximately 10%. Final diagnosis was primary acantholytic squamous cell carcinoma of the breast.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>This patient highlights the importance of thorough histopathologic and immunohistochemical evaluation to distinguish acantholytic squamous cell carcinoma of the breast from vascular mimics and other metaplastic carcinomas. The basal-like, hormone-receptor negative, HER2-negative, and low proliferative profile in this tumor underscores the heterogeneity of primary squamous cell carcinoma of the breast and the need for individualized treatment strategies.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1177\/10668969261461531","type":"journal-article","created":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T15:04:07Z","timestamp":1785942247000},"update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":0,"title":["Primary Acantholytic Squamous Cell Carcinoma of the Breast With Basal-Like Immunophenotype and Low Proliferation: A Case Report and Literature Review"],"prefix":"10.1177","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5358-3444","authenticated-orcid":false,"given":"Elif Kardelen","family":"\u00c7a\u011fda\u015f","sequence":"first","affiliation":[{"name":"Afyonkarahisar State Hospital"},{"name":"Institute of Biotechnology, Ankara University, Ankara, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Berkay","family":"\u00c7a\u011fda\u015f","sequence":"additional","affiliation":[{"name":"Afyonkarahisar State Hospital"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Emre","family":"Haf\u0131zo\u011flu","sequence":"additional","affiliation":[{"name":"Afyonkarahisar State Hospital"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"179","published-online":{"date-parts":[[2026,8,5]]},"reference":[{"key":"e_1_3_2_2_2","doi-asserted-by":"publisher","DOI":"10.12659\/AJCR.941448"},{"key":"e_1_3_2_3_2","doi-asserted-by":"publisher","DOI":"10.1111\/his.14091"},{"key":"e_1_3_2_4_2","doi-asserted-by":"publisher","DOI":"10.1007\/s10549-017-4251-3"},{"key":"e_1_3_2_5_2","doi-asserted-by":"publisher","DOI":"10.1177\/03000605231187936"},{"key":"e_1_3_2_6_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.clbc.2017.04.009"},{"key":"e_1_3_2_7_2","doi-asserted-by":"publisher","DOI":"10.1159\/000534847"},{"key":"e_1_3_2_8_2","doi-asserted-by":"publisher","DOI":"10.1080\/15384047.2020.1838033"},{"key":"e_1_3_2_9_2","doi-asserted-by":"publisher","DOI":"10.1159\/000519746"},{"key":"e_1_3_2_10_2","doi-asserted-by":"publisher","DOI":"10.1177\/10732748211044355"},{"key":"e_1_3_2_11_2","doi-asserted-by":"publisher","DOI":"10.1007\/s10549-014-3224-z"},{"key":"e_1_3_2_12_2","doi-asserted-by":"publisher","DOI":"10.4103\/jcrt.JCRT_303_17"},{"key":"e_1_3_2_13_2","doi-asserted-by":"publisher","DOI":"10.1186\/s12885-018-5212-x"},{"key":"e_1_3_2_14_2","doi-asserted-by":"publisher","DOI":"10.1002\/jso.2930590313"},{"key":"e_1_3_2_15_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.prp.2006.01.006"},{"key":"e_1_3_2_16_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.breast.2020.05.003"},{"key":"e_1_3_2_17_2","doi-asserted-by":"publisher","DOI":"10.2147\/CMAR.S250867"},{"key":"e_1_3_2_18_2","doi-asserted-by":"publisher","DOI":"10.1002\/cnr2.1391"},{"key":"e_1_3_2_19_2","doi-asserted-by":"publisher","DOI":"10.3389\/fphar.2024.1332574"},{"key":"e_1_3_2_20_2","doi-asserted-by":"publisher","DOI":"10.1093\/asj\/sjae023"},{"key":"e_1_3_2_21_2","doi-asserted-by":"publisher","DOI":"10.1007\/s12672-025-03107-9"},{"key":"e_1_3_2_22_2","doi-asserted-by":"publisher","DOI":"10.1177\/000313489906500519"},{"issue":"4","key":"e_1_3_2_23_2","first-page":"184","article-title":"Acantholytic variant of squamous carcinoma of the breast. A case report and review of literature","volume":"47","author":"Kajo K","year":"2011","unstructured":"Kajo K, Mach\u00e1lekov\u00e1 K, Kajo M, Z\u00fabor P. Acantholytic variant of squamous carcinoma of the breast. A case report and review of literature. Cesk Patol. 2011;47(4):184\u2013188.","journal-title":"Cesk Patol"},{"key":"e_1_3_2_24_2","doi-asserted-by":"publisher","DOI":"10.1007\/s00428-004-1163-5"}],"container-title":["International Journal of Surgical Pathology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/10668969261461531","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/full-xml\/10.1177\/10668969261461531","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/10668969261461531","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T08:40:58Z","timestamp":1787647258000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.1177\/10668969261461531"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,5]]},"references-count":23,"alternative-id":["10.1177\/10668969261461531"],"URL":"https:\/\/doi.org\/10.1177\/10668969261461531","relation":{},"ISSN":["1066-8969","1940-2465"],"issn-type":[{"value":"1066-8969","type":"print"},{"value":"1940-2465","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,5]]},"article-number":"10668969261461531"}}