[Alterations of connective tissue in granuloma anulare and in necrobiosis lipoidica. Microradiographic studies].

The microradiogram of granuloma anulare was compared with that of necrobiosis lipoidica. In the areas of cellular infiltration, the amount of connective tissue missing depended on the degree of infiltration. Apparently the collagenous bundles were destroyed, not pushed aside. In the necrobiotic type of necrobiosis lipoidica, the damage to collagenous tissue was more severe than one would have expected from the stained sections. The collagenous bundles were generally swollen, and there was a complete lack of normal high-density bundles in the damaged areas, in contrast to granuloma anulare and to the granulomatous type of necrobiosis lipoidica, however, the damage to the collagenous tissue seemed less severe in the microradiograms than in the stained sections. Differences between granuloma anulare and necrobiosis lipoidica were to be found in the microradiogram (see tables), but in general a differential diagnosis is only possible in severe cases, in spite of the different clinical picture.