RESUMEN
The results obtained in histochemical examination of the stroma of mammary gland carcinomas allow to draws the following conclusions. The reaction for alkaline phosphatase proved suitable for detecting proliferation zones in the stroma of mammary gland carcinoma. Proliferation of fibroblasts, myofibroblasts, endothelial cells, and possibly also of other cells is involved. At present, myofibroblasts can not be cytoenzymatically differentiated from fibroblasts. The reactions for acid phosphatase and nonspecific esterase provide a quick and reliable picture on the amount of macrophages. The combined reaction for alkaline phosphatase and dipeptidylpeptidase IV in the same section indicates that individual segments of the newly formed capillary bed in the stroma of the tumor, i.e. the arterial, intermediary and venous segment, are differentially equipped by these enzymes. The activity of several enzymes in carcinomal stroma with typical stripe- and wave-like architecture can most probably be assigned to fibroblasts and myofibroblasts. Between the enzymatic activity in the stroma and the type or differentiation of the carcinoma no relationship was established.