50% present as stage 3 or 4 diseases. M > F. Biphasic incidence, peaking in young adults and again in adults older than 55. Lymphocyte-rich Frequent mononuclear and diagnostic R-S cells; background infiltrate rich in T lymphocytes. R-S cells CD15+, CD30+; 40% EBV Uncommon. M > F; seen in older adults Lymphocyte depletion Reticular variant: Frequent diagnostic R-S cells and variants with a paucity of background reactive cells; diffuse fibrosis variant; hypocellular fibrillar background with scattered diagnostic R-S cells and variants and few reactive cells. R-S cells CD15+, CD30+; most EBV+. Uncommon. More common in older males, HIV infected individuals, and in developing countries. More likely to present with advanced disease. Lymphocyte predominance Frequent L & H (popcorn cell) variants in a background of follicular dendritic cells and reactive B cells, R-S cells CD20+, CD 15-, CD30-; EBV-. Uncommon. Young males with cervical or axillary lymphadenopathy. Mediastinal.">