Light micrograph of a pathologist biopsy, showing evidence of Hodgkin's disease. The presence of a characteristic binucleated cell, called Reed- Sternberg (central cell), is evidence of the disease. The specimen was taken from the pleural effusions of a 55 year old, male patient with insmixed cellularity Hodgkin's diseaseins. Hodgkin's disease is a cancer of the lymphoreticular system mechanisms & the immune response. The various cell lines of the system are all subject to cancerous changes. In Hodgkin's disease, the nature of the cell line is unknown, but in the most common form the cell population is mixed.