[Necrobiosis lipoidica (diabeticorum) and its association to Miescher's granulomatosis disciformis chronica et progressiva].

Morphologically, clinically and histologically the picture of necrobiosis lipoidica with and without diabetes represents an entity. In our opinion, granulomatosis disciformis chronica et progressiva Miescher reflects a specific reaction type of necrobiosis lipoidica being influenced by genetic factors. Its histological appearance is characterised by tuberculoid or sarcoid-like structures, in which the damage of the collagen as defined by necrobiosis, is variable but never absent. With regard to the factor of age, the concurrence of necrobiosis lipoidica sine diabete with granulomatosis disciformis Miescher in the middle of the period of life also speaks in favour of the similarity of both skin disorders. An injury seems to represent one of the conditional factors for the outbreak of the disease. The analysis of the histological slides revealed furthermore that the damage of the skin is confined to the clinically recognizable lesion. For its pathogenesis a local disturbance of the metabolism in the skin seems to be decisive i.e., the disturbance of the carbohydrate metabolism (shift from the citrate cycle to the pentosephosphate cycle, associated with the stimulation of fatty acid production). In the abnormal metabolism of the carbohydrates, the diabetes mellitus must be considered as the most important factor, however not excluding others as yet still unknown.