Progressive transformation of germinal centres is a histologic diagnosis and is clinically benign. The importance of its recognition is that this entity may antedate, occur simultaneously with, or follow a diagnosis of Hodgkin's lymphoma, particularly the nodular lymphocyte predominant subtype. PTGC has also been associated with other forms of Hodgkin's lymphoma including nodular sclerosis and mixed cellularity subtypes. Importantly, a diagnosis of PTGC should signal a need for close clinical follow-up of these patients and/or a repeat excisional biopsy should other sites of more significant lymphadenopathy be present.​