Friday 23 December 2011
The term ‘necrobiosis’ has been retained here because of common usage and refers to areas of altered dermal connective tissue in which, by light microscopy, there is blurring and loss of definition of collagen bundles, sometimes separation of fibers, a decrease in connective tissue nuclei, and an alteration in staining by routine histological stains, often with increased basophilia or eosinophilia. The term ‘collagenolytic’ granuloma is favored by others.
Granular stringy mucin is sometimes seen in such areas in granuloma annulare, and fibrin may be seen in rheumatoid nodules.
Necrobiotic areas are partially or completely surrounded by a histiocytic rim which may include multinucleate giant cells. In some cases histiocytes become more spindle-shaped and form a ‘palisade’.
rheumatic fever nodules
reactions to foreign materials and vaccines