Morphological Spectrum of Bone Marrow Aspirates in Infections: A Clinico-Hematological Analysis

Bone marrow examination (BME) is an invaluable tool for cases with pyrexia of unknown origin and pancytopenia. However, it is under-utilized for diagnosing infectious etiology and there is a paucity of literature regarding its role in infective pathology.

This study aims to bring to light the role of BME in diagnosing infectious pathology.

A retrospective study was carried out on bone marrow aspirates (BMAs) sent to the hematology department over the past 4 years. Clinical details, peripheral smears and BMA were retrieved from the records and analyzed.

Leishman-stained peripheral smears and BMA were studied along with bone marrow biopsy wherever feasible.

A total of 52 cases were studied. The most common clinical presentation was fever, clinical finding was splenomegaly and hematological finding was anemia. Based on the morphological findings in combination with clinical history, cases were categorized into-parasitic (26.9%), viral (23.1%), tubercular (11.5%), and nonspecific infections (38.5%). Parasites such as Leishmania donovani, microfilaria, plasmodium falciparum, and vivax were reported in 14/52 (27%) cases. Associated BMA findings were plasmacytosis, eosinophilia, reactive lymphocytosis, or dyserythopoiesis. In 38% (20/52) cases, no specific cause of infection was found in the bone marrow. These patients showed histiocytosis, hemophagocytosis, maturation arrest in myeloid lineage, relative myeloid hyperplasia, dysmyelopoiesis, toxic granulation/vacuolation in myeloid cells, lymphocytosis, increased plasma cells or monocytosis in marrow.

Increased histiocytes, hemophagocytosis, dysplastic changes, maturation arrest, relative myeloid hyperplasia or reactive plasmacytosis, lymphocytosis, and monocytosis are BMA features which must alert the pathologist towards an infectious disease process, a knowledge of these changes can help extend the scope of BME beyond hemato-lymphoid malignancies.