Presence of keratocysts allows for distinction (absent in eccrine carcinoma)
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Adenoid cystic carcinoma
Cribriform architecture allows distinction (generally absent in eccrine carcinoma)
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Infiltrative basal cell carcinoma
Lacks true lumen formation
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Typically negative for EMA and CEA
Often has epidermal attachments
May have other basal cell carcinoma subtypes
TERMINOLOGY
Synonyms
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Syringoid carcinoma, syringoid eccrine carcinoma, eccrine syringomatous carcinoma, eccrine epithelioma
Definitions
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Malignant adnexal tumor with eccrine differentiation somewhat resembling syringoma
No evidence of association with or development from syringomas
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Some authorities group these tumors with microcystic adnexal carcinoma (MAC)
CLINICAL ISSUES
Epidemiology
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Incidence
Very rare tumors
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Age
Usually present in middle-aged patients
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Sex
More common in women (3:1)
Site
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May also present on face, neck, trunk, or extremities
Presentation
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Typically present as plaque or nodule
May present as painful lesion ± alopecia
May be present for many years before diagnosis