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
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The infiltrate is usually separated from the epidermis by a pronounced "grenz zone" osit and consists largely of mature, small large lymphocytes, histiocytes, plasma cells, dendritic cells and eosinophils (6,7,8).
Dermis showing presence of granulomas containing lymphocytes, histiocytes, foamy macrophages containing bacilli, there is presence of grenz zone.
An excisional biopsy revealed diffuse monomorphic dermal infiltrate of small- to medium-sized atypical tumor cells which was separated from the overlying epidermis by a distinct Grenz zone (figure 3a and 3b).
Histopathologically, PCFCL is characterized by often dense proliferations of neoplastic follicle center cells, which are separated from the epidermis by a grenz zone (Figure 2, A and B).
In a subgroup analyses of those patients who had MM with cutaneous involvement, the presence of erythematous nodules (P = .004), multiple cutaneous lesions (P = .002), and the absence of a grenz zone (P = .004) were associated with reduced overall survival.
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).
Early lesions may demonstrate a "Grenz zone," which is a tumour-free region separating the tumour from the epidermis.
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.D., a dermatology resident at the University of California, Irvine, who presented the case at the annual meeting of the Pacific Dermatologic Association.