Hematological profile in pyrexia of unknown origin: role of bone marrow trephine biopsy vis-à-vis aspiration

Abstract

Background: Bone marrow examination, by aspiration and/or trephine biopsy, is an important procedure in arriving at a diagnosis for long-duration febrile illness. The role of trephine biopsy in immunocompromised host, especially HIV-positive patients, has been well studied in the literature. However, its utility in immunocompetent patients is still shrouded by controversy. Thus, the authors attempted to evaluate the utility of marrow aspirate vis-à-vis trephine biopsy in establishing a diagnosis in cases of pyrexia of unknown origin in immunocompetent individuals, along with an analysis of haematological alterations in these patients.Materials and methods: Over a period of 8 years, 121 patients with pyrexia of unknown origin underwent both bone marrow aspiration and trephine biopsy as a part of diagnostic work-up. These cases were reviewed for their clinical data and hematological findings, including detailed morphological features in aspiration smears and trephine biopsies. Bone marrow aspiration and biopsy were compared for their diagnostic efficacy in these patients.Results: A wide age range (2–65 years) was noted with a slight male predominance (2 : 1). Anemia was the most common feature in peripheral blood findings, seen in 97·5% of patients. Bone marrow aspiration was diagnostic in only 16·5% of cases, which revealed leishmaniasis or pure red cell aplasia. Granulomas were infrequent in marrow aspiration smears, as only two cases (1·6%) showed ill defined epithelioid cell collections. Compared to this, trephine biopsy offered a diagnosis in 76% of the cases. Granulomas were a frequent finding in the trephine biopsy, being present in 70% of the cases included. Additional cases diagnosed on biopsy (over those diagnosed with aspiration smears) included lymphoma, tuberculosis, fungal infection, sarcoidosis and hypocellular marrow.Conclusion: Bone marrow trephine biopsy is an important adjunct to aspiration in arriving at an aetiological diagnosis of patient with long-duration febrile illness, and should be routinely performed in such cases. The presence of granulomas in trephine biopsy increases the likelihood of an etiologic diagnosis in these patients.