Case 18 Female, 56 years. Pigmented lesion, skin of backShow diagnosis & comments
Combined naevus with mostly nonpigmented 'Blitz naevus' component
The centrobasal component of this lesion shows a cell cell type very similar to intradermal spindle-cell Spitz naevus cells. Since Spitz naevi and their variants typically show dimiuition in cellularity and cell size towards the base, an interpretation of this component as a non-pigmented blue naevus / deep penetrating naevus variant is preferred. The regular overall appearance, the absence of mitotic activity and the absence of significant nuclear atypia argue against melanoma.