Characteristic features of bone marrow metastasis from non-hematolymphoid malignancies

Background and objectives

Bone marrow metastasis (BMM) from non-hematolymphoid malignancies with resultant cytopenia(s) can mimic primary hematolymphoid disorders. This study aimed to investigate the clinical and pathological characteristics of BMM from non-hematopoietic tumors.

Methods

We conducted a retrospective cohort study of patients diagnosed with BMM by non-hematolymphoid malignancies at our institution over the past 10 years. Demographic and clinical characteristics, histopathological findings of bone marrow, types of metastatic tumors, and prognosis were analyzed.

Results

A total of 54 cases were included. The four most common malignancies with BMM, regardless of gender, were prostatic adenocarcinoma (29.6%), breast carcinoma (25.9%), colorectal adenocarcinoma (5.5%), and lung carcinoma (5.5%). The main clinical and laboratory manifestations were anemia (90.7%), reticulocytosis (80.5%), thrombocytopenia (73.9%), bone pain (55.5%), disseminated intravascular coagulation (39.6%), leukoerythroblastosis (35.3%), and leukopenia (24%). The vast majority (96.3%) of metastatic tumors were identified by morphology alone; however, in approximately 2.7% of cases, immunohistochemistry was required due to subtle morphologic features. In 29.6% (16/54) of patients, BMM was identified prior to or concurrently with other metastatic sites. The median time interval between the initial diagnosis of non-hematolymphoid malignancies and BMM was 29 months. Although patients who received anti-tumor treatment after BMM diagnosis showed significantly improved prognosis (P < 0.01), no significant differences were observed between those treated with immunotherapy versus chemotherapy and/or radiotherapy (P = 0.145).

Conclusions

Prostate and breast carcinomas are the most common malignancies associated with BMM, with anemia, reticulocytosis, and thrombocytopenia being the most frequent clinical manifestations. While our data demonstrate that anti-neoplastic treatments, regardless of regimen, significantly improve overall survival after BMM, no significant survival differences were observed when prostate and breast carcinomas were compared with other types of BMM.