Histogenic differentiation of polar tuberculoid granuloma and the "benign" or "malignant" behaviour of hanseniasis.

Based on a new morphological concept and classification of granulomatous inflammation: the polar granulomas, on the histogenesis of the tuberculoid granuloma of the positive Mitsuda test and on the relationship between the degree of histogenetic differentiation and behaviour of tumors, the Authors concluded that the "benign" or "malignant" behaviour of hanseniasis depends on the degree of tuberculoid differentiation of the lesions. If the lesion is histologically well differentiated toward a polar tuberculoid granuloma (tuberculoid hanseniasis) it will have a "benign" behaviour. On the contrary, if this differentiation is absent (virchowian hanseniasis) or poor (interpolar borderline hanseniasis) the behaviour of the lesion will be "malignant".