Frequency of bone marrow involvement in pyrexia of unknown origin

The definition of pyrexia of unknown origin (PUO) dates back to 1961; it was described as a persistent fever above 38.3°C (100°F) that evades diagnosis for at least 3 weeks, including 1 week of investigation in hospital.(1) The causes of PUO can be considered in four categories: infective, inflammatory, neoplastic and miscellaneous. The relative prominence of each category has changed over time, with an increasing proportion of patients who remain undiagnosed, which may be up to 51% of cases.(2) In cases where bone involvement is suspected, bone marrow biopsy can serve as a diagnostic tool , for example, myeloproliferative disorders, preleukemias (due to acute myelogenous leukemia), Gaucher’s disease, lymphoma, Erdheim-Chester disease, miliary tuberculosis, disseminated histoplasmosis, multicentric Castleman’s disease, Whipple’s disease, or typhoid/enteric fever.(3) A relationship between pyrexia of unknown origin and utilizing bone marrow biopsy as a diagnostic modality will be an eye opener for the clinicians. It will stress them to incorporate bone marrow biopsy as a part and parcel of the investigations. This study will also help to know the current spectrum of diseases causing PUO in patients in this region.It will help the clinicians in better assessment of the patients and expedite the diagnostic procedure that will ultimately decrease the misery of the patients.