Discrepancy was noted in about a fifth of the dogs
with evidence of neoplastic lymphocytes in either
blood or bone marrow, but not in both. A possible
explanation is that neoplastic cells entered blood circulation
from alternative sites such as the spleen or liver.
An additional consideration would be uneven distribution
of neoplastic cells within the bone marrow, resulting
in failure to detect large lymphocytes in some
specimens. However, a recent study evaluating the
presence of lymphoma based on bone marrow cytology
on aspirates collected in 2 different sites found
complete agreement between the 2 sites.