Granuloma faciale = الورم الحبيبي الوجهي |
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Clinically, granuloma faciale presents as one or several asymptomatic, soft, brown-red, slowly enlarging papules or plaques, almost always on the face of older individuals. Rare upper respiratory tract forms have been described .
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Histopathologic Features
A dense polymorphous infiltrate is present mainly in the upper half of the dermis but may extend into the lower dermis and occasionally even into the subcutaneous tissue. Quite characteristically, the infiltrate does not invade the epidermis or the pilosebaceous appendages but is separated from them by a narrow grenz zone of normal collagen . The pilosebaceous structures tend to remain intact. The polymorphous infiltrate consists primarily of neutrophils and eosinophils, but mononuclear cells, plasma cells, and mast cells also are present. Vascular damage in GF is seen but often is limited, and thus perhaps GF is best termed a neutrophilic vascular reaction . Frequently, the nuclei of some of the neutrophils are fragmented, especially in the vicinity of the capillaries, thus forming nuclear dust. Often, there is some evidence of vasculitis with deposition of fibrinoid material within and around vessel walls. Occasionally, some hemorrhage is noted. Foam cells and fibrosis frequently are observed in older lesions.
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Differential Diagnosis.
Granuloma faciale can appear similar to erythema elevatum diutinum, although a grenz zone and prevalence of eosinophils and plasma cells favors granuloma faciale. Other neutrophilic dermatoses can be distinguished from granuloma faciale by the lack of a grenz zone and clinical features. Frank leukocytoclastic vasculitis should not be seen in granuloma faciale. In acneiform lesions and folliculitides, pilosebaceous units are invaded by inflammatory cells and may be destroyed or disrupted.
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Pathogenesis.
Vascular damage may be important to the pathogenesis of this lesion because direct immunofluorescence data suggest an immune complex-mediated event with deposition of mainly IgG in and around vessels.
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