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Necrobiotic Xanthogranuloma: The cutaneous lesions of necrobiotic xanthogranuloma are basically
xanthogranulomatous in character (S12C21P11-1-6). Foamy histiocytes, including
Touton-type giant cells, are a prominent feature of the infiltrates. Areas of fibrosis and degeneration are relatively acellular; cholesterol clefts are a feature of such areas. Similar foci are common in
xanthomatous lesions of hyperlipidosis. Frank necrosis with fragments of the nuclei of inflammatory cells generally are not a feature. An associated paraproteinemia sets necrobiotic xanthogranuloma apart from
ordinary xanthoma. Patients in this category should be examined and followed for evidence of myeloma.
Miescher’s Granuloma:
In the category of palisaded granulomas, one clinical disorder, Miescher’s granuloma, remains nebulous. The lesions have a predilection for the face and scalp. In discussions of problem cases in which the basic patterns are those of a palisaded granuloma, older pathologists are most likely to suggest a diagnosis of Miescher’s granuloma. Recently, some authors have suggested that Miescher’s granuloma is nothing more than actinic granuloma; Mehregan confuses the two and uses the photomicrographs of actinic granuloma to document the histology of Miescher’s granuloma. The histology of “granuloma annulare” is variable. Some of the granulomas in the setting of collagen-vascular diseases could be accommodated in such a category but generally are afforded a separate identity; such lesions tend to have a component of neutrophils with greater regularity than is seen in classic lesions of granuloma annulare. The rheumatoid nodule might be cited as prototypic of the cellular response of palisaded granulomas in the setting of collagen-vascular diseases. Plasmacytosis is also a feature of such lesions in the setting of collagen vascular diseases; it is a most uncommon feature of the infiltrates in lesions of classic granuloma annulare. There is a tendency to characterize some of these lesions as atypical necrobiosis lipoidica. Figures S12C22aP12a-1-6 & S12C22bP12b-1-5 represent of case in which the changes might be cited as those favoring a diagnosis of Miescher’s granuloma.
Bel S, et al: Cerebrotendinous xanthomatosis. J Am Acad Dermatol 2001;45:292-5.
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