Abstract: Objective To analyze the clinical manifestations and hematologic parameters and observe the cytomorphological
features of metastatic tumors in the bone marrow originating from different primary sites. Methods The clinical data of 77
patients with bone marrow metasta tumors admitted between 2009 and 2014 between 2009 and 2014 in General Hospital of
PLA were studied retrospectively to analyze the indications of laboratory examinations (hematological laboratory tests, tumor
markers, peripheral blood films, and bone marrow aspirates). Results Of the 77 patients analyzed, 64.9% were over50 years of
age. The most common clinical characteristics were bone pain (65% ), anemia with thrombocytopenia (63.6% ) and
leukoerythroblastic reaction (61%). The hematological abnormalities included elevation of ESR, ALP, LDH, tumor markers, and
hypoproteinemia. Cytological examination of bone marrow aspiration samples revealed different morphological
characteristics of the metastatic cells from different primary sites; in most of the cases, scattered or clustered metastatic cells
and degenerative tumor cells were found on the edge of the bone marrow smears. Conclusion Detection of the primary tumor
site is difficult by cytological examination of bone marrow aspiration samples, but the cytological findings can be of value in
the diagnosis of neuroblastoma, small cell lung cancer and gastric cancer (signet ring cell carcinoma). A definite diagnosis of
bone marrow metastatic tumor relies on a combined evaluation of the disease history, clinical symptoms and laboratory
findings.