In MDS, the erythroid and megakaryocytic features are critical, as these lineages are not currently evaluable by flow cytometry. In lymphoma, partial involvement by lymphoma is important to document and other modalities cannot determine the architectural distribution of disease.
In plasma cell neoplasia, the number of plasma cells and their distribution is important in sub classifying MGUS, smoldering myeloma and plasma cell myeloma; this sub classification is critical in determining treatment requirements.