Mast cell histology

Mastocytosis is recognized in most patients because of the presence of characteristic cutaneous lesions [10]. A positive Darier s sign and/or histological examination of the skin using metachromatic stains, or by immunohistochemistry using antibodies to mast cell tryptase, helps confirm the diagnosis of cutaneous disease. 

Numerous reports, which rely chiefly on histochemical tests, have indicated that in pathological states of skin, especially in inflammation and malignancies, there is an increase in the level of acid mucopolysaccharides. High mucopolysaccharide contents of biopsy skin sections were demonstrated in chronic lupus (MIO) and in some cases of venous edema (Zl)j in scleroderma, however, the mucopolysaccharide content of the affected skin was low (MIO). Skin lesions from patients with lupus erythematosus, dermatomyositis, lichen sclerosus et atro-phicus, and poikiloderma showed significant increases in material which was stained histochemically (S20). In two cases of urticaria pigmentosa, hyaluronic acid was found in the histologically abundant mast cells (II) injection of hyaluronidase into the involved skin areas apparently cured the patients. An increased concentration of acid mucopolysaccharides has been obseri ed in sun-damaged skin (G5, SI, S12, S18). 

A 70-year-old woman took felodipine 10 mg/day and enalapril for about 1 year for hypertension. She developed telangiectatic lesions of both sides of the trunk. After excluding other causes, felodipine was withdrawn. After 2 months the lesions slightly abated, but never completely disappeared. The diagnosis was confirmed by histological evidence of enlarged capillaries parallel to the skin surface, in the absence of mast cells. 

VInen CS, Turner DR, Oliveira DB A central role for the mast cell In early phase vasculitis In the Brown Norway rat model of vasculitis a histological study. Int J Exp Pathol 2004 85 165-74. 

Mast cell heterogeneity in man. I. Histologic studies of the intestine. Int. Arch. Allergy Appl. Immunol. 76, 232-236. 

Histologic evidence shows a close anatomic correspondence between mast cells and G-fibers in peripheral organs (Skofitsch et al., 1985 Stead et al., 1987) and in the nodose ganglia (Undem and Weinrich, 1993). There is both functional and structural evidence for innervation of mast cells by C-fibers. Stimulation of the trigeminal nerve causes mast cells in the rat dura mater to degranu-late. This effect, which is apparent on histologic evaluation, is abolished by treatment with neonatal capsaicin and this may be mediated by C-fibers (Dimitriadou etal., 1991). 

HCV has been associated with many extrahepatic manifestations [35, 36, 67], including myocarditis and cardiomyopathy [68, 69]. Histological and functional observations have led to the hypothesis that mast cells play an important role in many fibrotic reactions [70-72], Potential mast cell-derived mediators of the fibrotic response include histamine, tryptase and TGF-fl, which stimulate fibroblast proliferation and collagen synthesis [73-75]. By producing these factors, chronic activation of cardiac mast cells by protein Fv may contribute to the heart fibrosis found in some patients with HCV infection [68, 69]. 

Histology Degranulated mast cells Cellular infiltrates including neutrophils Immunofluorescence shows antibody, complement, neutrophils Acute inflammatory reaction Mainly neutrophils Perivascular inflammation Mmnly mononuclear cells... 

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