Progressive transformation of germinal centers. Report of 2 cases and review of the literature.

Progressive transformation of germinal centers (PTGC) is a disease of mostly young adults that presents as unexplained, asymptomatic, localized or generalized lymphadenopathy which is usually persistent or recurrent over periods of many years. Histologically, the germinal centers contain a variable proportion of small mantle zone lymphocytes and thus become progressively transformed and may result in the loss of clear demarcation between them and the mantle zone. Here, we describe two cases of this disease and review the literature on the association of PTGC with lymphocyte-predominant Hodgkin's disease.