Background: So far, rare cases of B cell lymphoproliferative diseases with rod crystals inclusions had been reported.
Methods: Wright's stain and MPO stain are used for cell and rod crystal staining while the immunophenotype examination, fluorescence in situ hybridization probes, routine G-band cytogenetic analysis and molecular biological tests are used to diagnose the disease which is chronic lymphocytic leukemia.
Results: One to six colorless rod-like crystals can be seen in some mature lymphocytes of the peripheral blood smear and also colorless by MPO staining. The immunophenotype examination with flow cytometry shows it is consistent with chronic lymphocytic leuke mia/B small lymphocytic lymphoma.
Conclusions: The discovery of this rare phenomenon of rod-shaped crystallization in the peripheral blood may contribute to the diagnosis of lymphoproliferative diseases in B cells.