Signet-ring cells in a Waldenström's Macroglobulinaemia.

A case of signet-ring cell lymphoma affecting bone marrow is reported. The patient was diagnosed as Waldenström's Macroglobulinaemia on the basis of clinical and laboratory features including morphology, immunohistochemistry and gene rearrangement studies. Light microscopy examination showed cells contained large globular inclusions (signet-ring cells) that stained for kappa immunoglobulin light chain by immunohistochemistry. In addition, the neoplastic cells expressed the common leukocyte antigen CD45 and the B cell marker CD19. This to the best of our knowledge is the first report of a patient with Waldenström's Macroglobulinaemia with the presence of vacuolated signet ring- cells in the bone marrow. Differential diagnosis arises with non-haemopoietic tumours and this needs to be based on specific immunostaining. Tumours and this need to be based on specific immunostaining.