grenz zone

grenz zone

in histopathology, a narrow layer beneath the epidermis that is not infiltrated or involved in the same way as are the lower layers of the dermis.
[Ger. Grenze, borderline, boundary]
A well-demarcated zone of separation in the upper dermis delineated by the collagen of the flattened basal epidermis from the upper dermis, the latter of which often has a dense, usually lymphocytic infiltrate. A grenz zone is seen in granuloma faciale, lepromatous leprosy, and lymphocytoma cutis and may separate a pilar tumour or leiomyoma from atrophic overlying skin

grenz zone

a zone of relatively normal collagen demarcating the boundary between normal epidermis and a dermal lesion such as a granuloma or a neoplasm.
References in periodicals archive ?
Each case exhibited a well-defined grenz zone without epidermotropism.
In LL, a diffuse infiltrate of foamy macrophages and mast cells is present in the dermis below a subepidermal Grenz zone.
A skin biopsy from the leg's ulcer margin showed atrophic epidermis with Grenz zone, group of foam cells with some of lymphocyte cells, and vasculitis with endothelium occlusion of thrombus on the dermis.
Fite-Foraco staining was performed on the histopathological sections and examined for: (1) presence of granuloma--its location whether epidermal, dermal, or periappendiceal, mature or immature type, and predominant cell type of granuloma whether epithelioid or macrophage; (2) cellular infiltrate: predominant cell type, presence or absence of Langhans giant cells or foamy macrophages, and the distribution; and (3) other histopathological features such as obliteration of dermal nerves by granuloma, erosion of epidermis by granuloma, and presence or absence of grenz zone.
Histopathological examination showed significant epidermal atrophy and significant grenz zone and bundles of thin spindle like histiocytes with vortex arrangements with pyknotic nuclei and foamy cytoplasm were observed in the dermis (Figure 3).
There was a grenz zone between the tumor and the overlying epidermis, which was focally hyperplasia.
Biopsies showed increased Grenz zone collagen, as well as increased staining for mRNA for type I collagen.
Of note, there was a grenz zone, a sparing of the papillary dermis, which is characteristic of B-cell lymphoma," commented Jenny Murase, M.
Results showed a 50-80% increase in Grenz zone collagen (upper dermal collagen) in two of the three formulations designed to optimize growth factor penetration.
Most of the cases showed atrophic epidermis, 9 cases showed Grenz zone.
Distinguishing features such as epidermal hyperplasia, a grenz zone, and collagen trapping could assist in identifying this lesion.
13 Histoid lepromas are sudden eruptions of dome-shaped papules and nodules having characteristic epidermal grenz zone and dermal spindle-shaped histiocytes.