Laboratory Evaluation and Pathological Features of Bone Marrow Metastasis in Non-haematological Malignancies.

This study aimed to analyse the diagnostic accuracy of different laboratory parameters that can predict bone marrow metastasis. A cross-sectional analytical study was conducted at the Armed Forces Institute of Pathology (AFIP), Rawalpindi from March 2021 to August 2021. Bone marrow aspirates and biopsy procedures were done on 60 newly diagnosed cases of non-haematological malignancies as part of staging. Laboratory parameters noted for the study included peripheral blood smear findings, serum lactate dehydrogenase (LDH), radiological findings, and bone marrow aspirate/trephine biopsy results. Bone marrow metastasis was seen in 21/60 patients. The most common malignancies with bone marrow involvement were retinoblastoma and neuroblastoma. Laboratory findings showed no significant statistical difference in mean haemoglobin and total leukocyte count between cases and controls. Positive cases had a mean platelet count of 261.7 x 109/L and mean LDH of 750.1 U/L (p <0.05) for both parameters. ROC analysis showed the area under the curve (AUC) for LDH to be 0.969 (highly significant) showing a strong predictive value of LDH. Positive radiological findings were detected in only one case with bone marrow metastasis. The elevated level of serum LDH is not only cost-effective but also has high diagnostic accuracy to predict bone marrow metastasis. Key Words: Bone marrow, Biochemical, Lactate dehydrogenase, Metastasis, Non-haematological malignancies.