Richter's syndrome: Literature and original data

Aim. Review of literature data and original experience with Richter's syndrome. Materials and methods. 250 patients suffering from malignant lymphoproliferative diseases with blood and bone marrow lymphocytosis were observed. 8(3.2%) of them developed diffuse large-cell lymphoma (criteria and classification of REAL). Results, 5 of the above 8 patients demonstrated spontaneous regression of lymphocytosis. These cases may illustrate transformation (clonal progression) of one morphological variant of malignant non-Hodgkin's lymphoma into another one, more aggressive. For this rare variant of Richter's syndrome running with regression of lymphocytosis the term Richter-Lortolary syndrome is proposed. Lortolary was the first who revealed a decrease of lymphocytosis in Richter's syndrome. The studies of the genome structure, first of all, of immunoglobulin genes show that in Richter-Lortolary syndrome it is easier to confirm monoclonality of the two tumors (lymphocytic and large-cell) than to reject it. However; the idea of transformation has not been confirmed morphologically yet. Conclusion. Development of diffuse large-cell lymphoma in the course of chronic lymphatic tumor does not always indicate terminal state, later stage of tumor progression and poor prognosis.