Background: Hematological disorders are heterogeneous conditions ranging from malignant to non-malignant disorders. Hematological malignancies comprise a collection of heterogeneous conditions originating from cells of the bone marrow and the lymphatic system. Therefore, this study aimed to determine the pattern of bone marrow confirmed malignant and non-malignant hematological disorders in patients with abnormal hematological parameters. Methods: Institutional-based cross-sectional study was conducted in Dessie town from April 2020 to June 2021. A total of 228 study participants who had abnormal hematological parameters and referred for bone marrow examination were included consecutively. About 1.5 mL of bone marrow sample and 3 mL of venous blood sample were collected for bone marrow examination, complete blood count analysis and peripheral blood morphology examination. Wright stain, Sudan black B, and Prussian blue stains were used for staining the bone marrow and peripheral blood smears. The result was expressed in mean and standard deviation and presented in texts and tables. Ratio, frequency, and percentage were used to express the magnitude of malignant and non-malignant hematological disorders. Results: The overall prevalence of hematological malignancies among the study participants was 11.4% with 8.8% in male patients. The prevalence of hematological malignancies were 3.5% CML, 2.6% AML, 1.8% CLL and MM, 0.9% ALL and undifferentiated acute leukemia. On the other hand, 57.0% of the study participants had non-malignant hematological disorders. Regarding non-malignant hematological cases, 24.6% were erythroid hyperplasia, 10.5% aplastic anemia, 8.8% concomitant IDA and MBA, 7.0% MBA, 3.5% leukemoid reaction, 1.8% IDA, and 0.9% visceral leishmaniasis. In patients with HM, 66.7% of AML, 100% of CML and CLL, and 75% of MM patients had increased total WBC count, whereas 66.7% of AML, 62.5% of CML, 75% of CLL, and 50% of MM patients had decreased hemoglobin level. On the other hand, 66.7% of AML, and 50% of CML, ALL, and CLL patients had decreased platelet count. Conclusion: In this study, 11.4% of the patients had hematological malignant cases, whereas 57% of the patients had non-malignant hematological cases. Therefore, in patients with hematological abnormalities and where conclusive diagnosis could not be made through clinical and other laboratory investigations, bone marrow examination should be done for definitive diagnosis, management and prognosis.
