Retroperitoneal Lymphoma with Ribosome-Lamellae Complexes, Cytoplasmic Projections, and Desmosome-like Junctions: An Ultrastructural Study

The ultrastructural finding of ribosome-lamellae complexes (RLC) in 15% of tumor cells in an unusual retroperitoneal lymphoma is reported. Tumor cells had numerous nuclear pockets, cytoplasmic projections, and, not infrequently, desmosomelike attachments. RLC were similar to those previously described in patients with hairy cell leukemia and less often in other leukemia types, with the basic configuration of a hollow cylinder. An intimate association with the rough endoplasmic reticulum was evident. A review of the literature disclosed only one other reported lymphoma with similar structures.