title: Melanoma Margin Assessment.
abstract: Primary cutaneous melanoma is treated by excisional surgery and careful histologic assessment of the specimen margins is a crucial component of pathology reporting. Surgical margins may be assessed by conventional transverse (bread-loaf) vertical sections, by en face vertical sections, or by en face oblique sections. Transverse techniques only sample a small percentage of the surgical margin. En face techniques are technically challenging but allow assessment of close to 100% of the margin. Margin assessment for melanoma removed from chronically sun-damage skin is difficult. Melanoma in situ shows contiguous melanocyte growth, nesting, or intraepidermal pagetoid spread. Pitfalls include solar melanocytic hyperplasia, solar lentigines, melanocytic hyperplasia secondary to previous biopsy, lichenoid reactions, and invasive melanoma mimicking scar or benign nevus. En face sections can be used to assess margins for melanoma on sun-damaged skin, and evidence suggests that frozen sections may also be employed by experienced clinicians. Immunohistochemistry is a useful ancillary technique, enabling more accurate identification of in situ melanoma within a surgical margin.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Calgary, Calgary Laboratory Services, 9-3535 Research Road NW, Calgary, Alberta, Canada T2L 2K8. Electronic address: martin.trotter@cls.ab.ca.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Trotter
keywords: Frozen sections; Immunohistochemistry; Margin assessment; Melanoma in situ; Zentigo maligna