Azorides R. Morales

In the diagnostic evaluation of soft tissue tumors, more than in any other group of neoplasms, a large number of special diagnostic procedures are often performed. The application of these diagnostic tools underlines the difficulties in distinguishing undifferentiated carcinoma from sarcomas and one histogenetic type of sarcoma from another. In fact, the various histogenetic types of sarcomas have overlapping morphologic features, which is understandable since these mesenchymal neoplasms have a common cellular ancestor, the primitive mesenchymal neoplasms have a common cellular ancestor, the primitive mesenchymal cell undergoes proliferation and cellular differentiation which replicates the stages of development of its non-neoplastic counterpart. According to the cellular line of differentiation, during these various stages of development, a variety of different cytoplasmic products are elaborated. It follows therefore, that demonstration of these various cytoplasmic products could lead to histogenetic diagnosis. Consequently, the value of any one given “special stain” will depend on whether or not it demonstrates the characteristic cytoplasmic materials associated with these tumors.