Though not very frequent, BM is one of the important
sites of metastasis of solid tumors. The involvement of the
BM is not only a sign of diffuse hematogenous spread of the
tumor; it also results in cytopenias that increase the risk of
bleeding and infection. Cytopenias also hinder the delivery
of effective anti-neoplastic treatment, as almost all chemotherapeutics
have at least some degree of hematotoxicity.
All these factors add up to yield a worse prognosis for the
patient who has BM metastasis.
Magnetic resonance imaging can give some clues on the
involvement of BM and the definitive diagnosis depends
on histopathological examination of BM biopsies. Immunohistochemical
studies as well as molecular techniques like
polymerase chain reaction have enabled us to detect metastatic
cells in the BM, even if they are in minute quantities
. Though these methods are gaining popularity, they require
much more effort, time and money than the conventional
techniques. The clinical significance of microscopical
involvement of the BM also remains to be established. Morphological examination of the BM aspiration is much
less sensitive than the latter methods, yet it remains the easiest,
cheapest and least time consuming procedure for the
diagnosis of clinically suspected BM involvement.
Theoretically, all tumors can metastasize to the BM,
however, cancers of the breast, prostate and lung are the
most frequently encountered ones in adults [5-7]. In pediatric
cases, neuroblastoma is responsible for the majority of
cases. In a retrospective study, Mohanty et al.  showed
that prostate cancer (47.8%) was the most common tumor
among adults, followed by breast cancer (28.2%). In this
series, all pediatric cases had neuroblastoma. In another
study, these findings were confirmed: Neuroblastoma was
the most common primary tumor in children, followed by
breast and prostate cancers in adults .
In our study, we reviewed the results of 3842 patients
who had a BM aspiration. We found 73 cases with BM
metastasis of solid tumors. Breast and lung cancers were
the most commonly encountered tumors. In contrast to the
literature, we had only 5 cases of prostate cancer (6.8%).
Though this may at least in part be due to a lower incidence
of prostate cancer in our country than in more developed
countries, it probably results from the small number of patients
followed in our clinic, as most prostate cancer patients
are treated by urologists in our country.
Patients with BM involvement could have normal blood
counts, some disturbances in one or more series or they
could be pancytopenic. Though severe anemia can be lifethreatening,
the complications of neutropenia and thrombocytopenia result in more morbidity and mortality. Pancytopenic
patients are known to have a higher complication
risk than the others. In a study, the authors have reported
six cases with tumors metastatic to the BM . Of these,
4 patients (67%) had anemia, 5 (83%) had thrombocytopenia
and 3 (50%) had leucopenia. In our study, the figures
that we have observed are somewhat smaller: Anemia was
observed in 68.5%, leukopenia in 23.3% and thrombocytopenia
in 58.9% of the patients, while 17.8% of patients had
pancytopenia, 37.4% bicytopenia, and %13.9 had normal
counts. These findings suggest that in our institution, bone
marrow aspiration is done in patients with less profound
Median survival of the patients with thrombocytopenia
was significantly shorter than those without thrombocytopenia.
This finding may be related to amount of bone marrow
involvement, long lasting recovery of thrombocytopenia
that leads to hemorrhagic complications and death.
The four parameters, which are strongly correlated with
marrow involvement, were the leukoerythroblastic blood
pattern, a serum lactic dehydrogenase over 500 IU/liter, a
platelet count under 100,000/microliter, and bone pain .
BM involvement by solid tumors carries a poor prognosis,
especially when thrombocytopenia is present. Aspiration
of the BM provides an easy and quick way of detecting
involvement, however, biopsy with immunohistochemical
and/or molecular techniques may be needed in case of microscopical