A 20-year-old male presents in the emergency room with a lymphoma involving the mediastinum that is producing respiratory distress. The lymphocytes are most likely to have cell surface markers characteristic of which of the following?
High-Yield Explanation
T cell lymphomas occurring in the thoracic cavity in young patients usually arise in the mediastinum and have a paicularly aggressive clinical course with rapid growth in the mediastinum impinging upon the trachea or mainstem bronchi and leading to marked respiratory deficiency, which can in turn lead to death in a relatively sho period of time if not treated. These unique lymphomas are characterized by rapid cell growth and spread into the circulation, where they produce elevated total white counts reflected by circulating lymphoma cells. As T cells they have characteristics of rosette formation with sheep blood cells. T cells also have subtypes and subsets, which can be delineated by monoclonal antibodies as CD4 helper and CD8 suppressor (cellular differentiation) T cell surface antigens. The tumor cells also express IL-2 receptor. Fc receptors occur on B cells and macrophages. Class II HLA antigens can be found on macrophages, Langerhans cells, and dendritic reticulum cells. Reference: Robbins & Cotran Pathologic Basis of Disease, 9edition.