Visualization of the ribosome-lamella complex in plastic-embedded biopsy specimens as an aid to diagnosis of hairy-cell leukemia.

Hairy-cell leukemia is a lymphoid leukemia of B-cell lineage, the cells of which are characteristically tartrate resistant acid phosphatase positive on blood and bone marrow smears. However, because hairy-cell leukemia is frequently associated with abundant marrow stroma, dry marrow taps, and peripheral pancytopenia, the diagnosis may rest on the appearance of the bone marrow biopsy specimen alone. The ribosome-lamella complex has been associated with hairy-cell leukemia, and can be visualized by light microscopy using l-micron sections of plastic-embedded bone marrow specimens stained with toluidine blue. We describe the findings in a case in which bone marrow and liver biopsy specimens were positive for hairy cells containing ribosome-lamella complex, which were visualized with both electron microscopy and light microscopy. Reliable light microscopic identification of ribosome-lamella complex may provide an easy and inexpensive method of aiding in the diagnosis of hairy-cell leukemia when aspirate material is not available for tartrate-resistant acid phosphatase stain.