This CD-ROM is intended, above all, to aid practitioners and postgraduate students of pathology in establishing a diagnosis and in their own assessment of a tumor. The most important tumors and pseudo-tumors of soft tissue are illustrated by gross, microscopic and immunohistological studies. Almost all tumors described in classical treatises and in the WHO classification are presented, together with recently reported entities, for which histogenesis is still a matter of debate or whose existence is even denied. Tumors which may resemble soft tissue tumors (such as stromal tumors of the digestive tract, mesenchymatous or mixed mullerian tumors) are also illustrated for purposes of comparison and differential diagnosis.