title: Tamoxifen-induced eccrine squamous syringometaplasia.
abstract: A 74-year-old woman had carcinoma of her right breast for which surgery was performed. Four weeks following the start of tamoxifen therapy, she developed papules and plaques over her face, trunk and limbs. A skin biopsy showed perivascular and periadnexal mixed inflammatory cellular infiltrate with fibroplasia. Notably, the dermis also showed squamous epithelial islands, which in foci were noted to be closely associated with eccrine epithelium. This was confirmed with double peroxidase - alkaline phosphatase immunohistochemistry - the eccrine lumina highlighted with carcinoembryonic antigen (polyclonal) and the squamous metaplasia positive for cytokeratin 5/6. Eccrine squamous syringometaplasia was diagnosed. With close clinicopathological correlation, the cutaneous eruption was attributed to tamoxifen. Following discontinuation of the drug, the eruption resolved. Eccrine squamous syringometaplasia has been reported to occur in association with diverse conditions, including skin ulcers, burns and as a cutaneous adverse drug reaction, most commonly to chemotherapeutic drugs. This is believed to be the first report involving tamoxifen.
authors.affiliation: University Medicine Cluster, National University Health System, Singapore.
authors.forename: David C-W
authors.initials: DC
authors.lastname: Teoh
authors.forename: Derrick C-W
authors.initials: DC
authors.lastname: Aw
authors.forename: Huma
authors.initials: H
authors.lastname: Jaffar
authors.forename: Winnie
authors.initials: W
authors.lastname: Ling
authors.forename: Wei-Peng
authors.initials: WP
authors.lastname: Yong
authors.forename: Yoke-Sun
authors.initials: YS
authors.lastname: Lee
authors.forename: Shoa-Nian
authors.initials: SN
authors.lastname: Choo
authors.forename: Kong-Bing
authors.initials: KB
authors.lastname: Tan
mesh_terms: D000368:Aged; D018931:Antineoplastic Agents, Hormonal / Q000008:administration & dosage / Q000009:adverse effects*; D001943:Breast Neoplasms / Q000628:therapy; D020405:Dermis / Q000378:metabolism / Q000473:pathology; D003875:Drug Eruptions / Q000378:metabolism / Q000473:pathology; D004439:Eccrine Glands / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D008679:Metaplasia; D013629:Tamoxifen / Q000008:administration & dosage / Q000009:adverse effects*
chemical_list: D018931:Antineoplastic Agents, Hormonal; D013629:Tamoxifen