{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,31]],"date-time":"2025-12-31T16:11:01Z","timestamp":1767197461348,"version":"3.48.0"},"reference-count":13,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2025,12,30]],"date-time":"2025-12-30T00:00:00Z","timestamp":1767052800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Dermatopathology"],"abstract":"<jats:p>Reticulated acanthoma with sebaceous differentiation (RASD) is a rare, benign cutaneous neoplasm. Its variable clinical presentation frequently mimics both benign and malignant entities, posing a significant diagnostic challenge. We report a case of pigmented RASD in a 78-year-old Malay male of Fitzpatrick skin type IV who presented with a 5-year history of an 8 \u00d7 5 mm deeply pigmented, asymmetrical nodule on the left upper back, with a 2 mm central raised area showing less pigmentation. The lesion was clinically suspicious for malignant melanoma. Histopathological examination revealed characteristic features of RASD: a broad, plate-like, reticulated and pigmented epidermal proliferation with clusters of mature sebocytes at the bases of anastomosing rete ridges. Following biopsy confirmation, the residual lesion is being managed conservatively with observation. This case demonstrates an unusual heavily pigmented clinical presentation that completely obscured the typical yellowish hue associated with sebaceous differentiation, highlighting pigmented RASD as an important diagnostic pitfall in patients with skin of color. In conclusion, RASD should be included in the differential diagnosis of pigmented cutaneous lesions, especially in patients with skin of color. Recognition of this benign entity can prevent unnecessary aggressive surgical intervention.<\/jats:p>","DOI":"10.3390\/dermatopathology13010004","type":"journal-article","created":{"date-parts":[[2025,12,31]],"date-time":"2025-12-31T15:30:32Z","timestamp":1767195032000},"page":"4","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Deeply Pigmented Reticulated Acanthoma with Sebaceous Differentiation Mimicking Cutaneous Malignancy: A Case Report and Review of the Literature"],"prefix":"10.3390","volume":"13","author":[{"given":"Padol","family":"Chamninawakul","sequence":"first","affiliation":[{"name":"National Skin Centre, Singapore 308205, Singapore"},{"name":"Institute of Pathology, Department of Medical Services, Ministry of Public Health, Bangkok 10400, Thailand"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5423-0635","authenticated-orcid":false,"given":"Xiaotian","family":"Wu","sequence":"additional","affiliation":[{"name":"National Skin Centre, Singapore 308205, Singapore"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Joyce S. S.","family":"Lee","sequence":"additional","affiliation":[{"name":"National Skin Centre, Singapore 308205, Singapore"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,12,30]]},"reference":[{"key":"ref_1","unstructured":"Steffen, C., and Ackerman, A.B. (1994). Reticulated acanthoma with sebaceous differentiation. Neoplasms with Sebaceous Differentiation, Lea & Febiger."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"158","DOI":"10.1097\/01.dad.0000199879.63857.dc","article-title":"Reticulated acanthoma with sebaceous differentiation","volume":"28","author":"Fukai","year":"2006","journal-title":"Am. J. Dermatopathol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"TS5","DOI":"10.1016\/j.ad.2022.10.030","article-title":"Reticulated Acanthoma with Sebaceous Differentiation","volume":"113","author":"Valencia","year":"2022","journal-title":"Actas Dermo-Sifiliogr."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"391","DOI":"10.1097\/DAD.0b013e318191cafc","article-title":"Reticulated acanthoma with sebaceous differentiation. Lack of association with Muir-Torre syndrome","volume":"31","author":"Haake","year":"2009","journal-title":"Am. J. Dermatopathol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"35","DOI":"10.5826\/dpc.0703a07","article-title":"Reticulated acanthoma with sebaceous differentiation mimicking melanoma","volume":"7","author":"Ribeiro","year":"2017","journal-title":"Dermatol. Pract. Concept."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1016\/j.jdcr.2021.03.018","article-title":"Reticulated acanthoma with sebaceous differentiation","volume":"11","author":"Molinelli","year":"2021","journal-title":"JAAD Case Rep."},{"key":"ref_7","first-page":"63","article-title":"Superficial epithelioma with sebaceous differentiation: A case report with literature review","volume":"26","author":"Coelho","year":"2017","journal-title":"Acta Dermatovenerol. Alp. Pannonica Adriat."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"e71","DOI":"10.1111\/ajd.12058","article-title":"Reticulated acanthoma with sebaceous differentiation: Another sebaceous neoplasm associated with Muir-Torre syndrome?","volume":"55","author":"Shon","year":"2014","journal-title":"Australas. J. 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Dermatol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"e46426","DOI":"10.1097\/MD.0000000000046426","article-title":"Reticulated acanthoma with sebaceous differentiation: A case report","volume":"104","author":"Yu","year":"2025","journal-title":"Medicine"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"562","DOI":"10.1684\/ejd.2021.4088","article-title":"Bowen\u2019s disease occurring on a reticulated acanthoma with sebaceous differentiation: Possible malignant transformation","volume":"31","author":"Yoshida","year":"2021","journal-title":"Eur. J. Dermatol."}],"container-title":["Dermatopathology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2296-3529\/13\/1\/4\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,31]],"date-time":"2025-12-31T16:09:01Z","timestamp":1767197341000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2296-3529\/13\/1\/4"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,12,30]]},"references-count":13,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2026,3]]}},"alternative-id":["dermatopathology13010004"],"URL":"https:\/\/doi.org\/10.3390\/dermatopathology13010004","relation":{},"ISSN":["2296-3529"],"issn-type":[{"value":"2296-3529","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,12,30]]}}}