Lymphomas and their expression in peripheral blood

Circulating malignant cells may be demonstrated in patients with lymphoma. Whereas Hodgkin's disease rarely if ever becomes leukemic, the non-Hodgkin's lymphomas often express varying numbers of neoplastic cells in peripheral blood. The incidence of leukemic manifestation in these patients correlates with the histologic subtype of the lymphoma. Pure morphologic examination of neoplastic circulating cells may not be sufficient to recognize the presence of lymphoma or to diagnose its type. The application of modern laboratory techniques such as enzyme histochemistry, cell surface markers and cell kinetics, may be very helpful in demonstrating the presence of circulating lymphoma cells in recognizing their type.