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Having, or arranged in, three zones or layers.
References in periodicals archive ?
A prototypic histologic pattern of RN was described as consisting of a junctional melanocytic component with varying degrees of pigmentation overlying fibrous scar tissue and deep, residual, monomorphous nevus cells lacking mitotic figures (2); this pattern would later be termed trizonal.
3,17) The trizonal histologic pattern of RN has been confirmed in many studies (2-4,6,17) (Figures 1 and 2).
31) Irrespective of nomenclature, these lesions are histopathologically characterized by a trizonal pattern consisting of (1) atypical junctional proliferation of melanocytes with pagetoid spread above the basal layer; (2) prominent dermal fibrous scarlike tissue containing large, irregular, and confluent melanocytic nests; and (3) residual nevus cells adjacent to or below the scar.