Lymphoproliferative disorders of the T-cell series. A review.

Malignant diseases of the hematopoietic and lymphoid systems have been the subject of vigorous study in recent years. New methodologies, along with conventional techniques for identifying cell markers, now enable us to identify malignant cells with much greater specificity than in the past. Cell marker analysis has begun not only to extend our understanding of normal cell differentiation in the lymphoid and hematopoietic systems, but also to furnish more practical guidelines for approaching malignant disease, including more objective and reproducible classification, more accurate diagnosis and prognosis, more appropriate and more effective choice of treatment. Neoplasms of the T-cell series, which are the subject of this presentation, have in the past received less attention than the B-cell malignancies. More recent literature, however, shows increasing use of modern techniques in the analysis of T-cell malignancies, along with a corresponding increase in clinical resourcefulness. Different phenotypes of malignant cells have been correlated with the heterogeneous clinical and pathological features of T-cell neoplasms, suggesting a basis for their inconsistent responsiveness to treatment. As we develop a uniform system of classification and a generally accepted terminology for these heterogeneous and frequently puzzling disorders, we hope to gain further insight into pathogenetic mechanisms of the T-cell neoplasms, and to refine therapeutic measures for diseases which have defeated conventional therapy in the past.