KAPOSIS-SARCOMA OF INTERNAL ORGANS - A MULTIPARAMETER STUDY OF 86 CASES

Background. During the past decade, Kaposi's sarcoma (KS), one of the most common acquired immune deficiency syndrome-defining diseases, has been the subject of sustained research, However, basic questions abou t its etiology, histogenesis, growth, and dissemination remain unanswe red. Even its nature, whether hyperplasia or neoplasia, is still contr oversial. Most studies and concepts to date have been based on dermato logic KS. The present study, in contrast, examines by various paramete rs a series of patients with KS of internal organs. Materials and Meth ods. The series includes 86 cases (39 surgical specimens and 47 autops ies) of visceral and disseminated KS. The study is focused on the gros s distribution of lesions, the mode of dissemination, the histologic p atterns, and the cellular immunophenotypes, which are investigated wit h the use of 18 monoclonal antibodies. Results. The involvement of var ious organs, multiplicity of lesions, and progression of tumors were r ecorded. Seven histologic patterns forming a spectrum of cellular diff erentiation were distinguished. Immunophenotypes characteristic for di fferent histologic patterns were recognized. Although some cell marker s such as those recognized by antibodies against Factor VIII R-Ag, Act in, and Ulex europaeus were restricted to the well differentiated KS c ells, others including CD34 and CD31 demonstrated a strong affinity fo r the entire spectrum of KS cell differentiation. Conclusion. The pres ent study of KS of internal organs revealed that poor grades of histol ogic and immunophenotypic differentiation correlated with invasion and dissemination, which are fundamental characteristics of malignant tum ors.