Bone Marrow Examination in the Diagnosis of Infectious Pathology: An Often Underutilized Diagnostic Tool

Bone marrow examination (BME) is one of the most important investigations in patients presenting with pyrexia of unknown origin (PUO) and cytopenias.

This study aimed to assess the diagnostic yield of BME in infectious etiologies, determine their spectrum, and characterize the associated hematological and reactive marrow morphological changes.

It is a retrospective study, done on available data of all the infections diagnosed on the BME of six years, from January 2018 to December 2023. The clinical features and hematological findings were recorded. Cellularity of marrow, morphology of trilineage hematopoiesis, cell count, hemophagocytosis, iron stores, presence of organisms, and granulomas were evaluated.

A total of 29 cases of infections were diagnosed, and the most common infection diagnosed was leishmaniasis in 19 (65.5%) cases, followed by tuberculosis and histoplasmosis seen in three (10.3%) cases each. Two (6.8%) cases showed infiltration of bone marrow by Hansen's disease, and one case each of cryptococcosis and disseminated Mycobacterium avium intracellulare infection. Anemia was the most common hematological finding, followed by thrombocytopenia, pancytopenia, and leukopenia. On BME, the prominence of histiocytes followed by erythroid hyperplasia and plasmacytosis was the most common reactive change.

BME is a simple, rapid, and economical diagnostic modality to diagnose infections. The presence of an organism has to be ruled out with bone marrow aspiration (BMA)/biopsy with anemia and plasmacytosis for PUO. Careful scrutiny of BMA slides is essential to identify soft clues that indicate an underlying infection. It plays a pivotal role in cases of PUO, particularly when other diagnostic modalities are inconclusive or when a rapid diagnosis is essential to enable timely management.