Because they are relatively uncommon, lymph node based peripheral T cell lymphomas present a considerable diagnostic challenge to the practicing pathologist. These tumors have a morphologic spectrum that overlaps considerably with reactive lymphoid hyperplasia, B cell lymphomas and Hodgkin lymphoma. This practically oriented course will focus on the major categories of lymph node based peripheral T cell lymphomas recognized by the World Health Organization Classification of Tumors of Lymphoid Tissues: angioimmunoblastic T cell lymphoma, anaplastic large cell lymphoma and peripheral T cell lymphoma, unclassified, adult T cell leukemia/lymphoma. Diagnostic strategies for approaching T cell neoplasms using a combined clinical, morphologic, immunophenotypic and genetic approach will be discussed. The morphologic diversity of peripheral T cell lymphomas and the diagnostic criteria for the benign and malignant processes in the differential diagnosis of T cell lymphoma will be presented.

The course will be constructed as a general introduction followed by a series of case presentations. It is intended for pathologists in training, practicing general pathologists and subspecialists in hematopathology. Course participants will receive a detailed syllabus and bibliography and a CD-ROM containing pertinent course material, including images of the presented cases and the other entities discussed in the course. At the completion of the course the participants will: 1) be able to utilize a rational, cost-effective strategy combining morphologic, phenotype, and genetic data to approach T cell malignancies, 2) be able to accurately diagnose lymph node based peripheral T cell lymphomas and distinguish them from reactive processes, 3) understand the clinical implications of the diagnoses and 4) understand the biologic aspects of T cell immune reactions, angioimmunoblastic T cell lymphoma, anaplastic large cell lymphoma and peripheral T cell lymphoma, unclassified, and adult T cell leukemia/lymphoma. (New Course)