Clonality and Lymphoproliferative Lesions

It is much easier for the hematologist or oncologist to arrive at a diagnosis explaining lymphocytosis, lymphadenopathy, or abnormal lymphocytic infiltrations of bone marrow or skin if the cells involved can be shown to originate from a clone. Attempts to define the clonality of cells in lymphoproliferative lesions have usually followed one of three standard approaches: the determination that only a single immunoglobulin light chain, either kappa or lambda, is expressed; the demonstration of a specific cytogenetic abnormality; or the expression of only a single allele for glucose-6-phosphate dehydrogenase within the tumor of a female patient who is heterozygous for…