Haematological remission of leukaemic polymorphic immunocytoma following splenectomy. Case report with longitudinal immunological and cytogenetic studies.

A 56-year old man with a Rai stage IV B-cell chronic lymphocytic leukaemia (polymorphic immunocytoma according to the Kiel classification) of mu kappa-phenotype with a clonal chromosomal abnormality in cells from peripheral blood, bone marrow, and spleen is reported on. Following splenectomy (without further therapy) the blood lymphocytosis gradually decreased to normal and the patient entered a remission, assigned 42 months after splenectomy by immunological and cytogenetic studies that revealed no cells of clonal origin in blood or bone marrow. Utilizing cellular markers of clonality, we thus confirm that haematological remissions may follow splenectomy. A subsequently developed orbital lymphoma (without leukaemia) consisted of tumor cells derived from the initial leukaemia cell clone as indicated by their immune and cytogenetic phenotype. The case report is discussed in relation to previous reports on "spontaneous" remissions of lymphoid leukaemias.