Quality and Diagnostic Characterization of Bone Marrow Biopsies at Kamuzu Central Hospital, Malawi: A Retrospective Study

PURPOSE Diagnosis and management of many hematologic diseases depends on BM evaluation though data on diseases diagnosed and quality of bone marrow biopsies from Malawi is limited. METHODS We conducted a retrospective study of bone marrow biopsies taken for routine care from 2013-2023 at Kamuzu Central Hospital in Lilongwe, Malawi. We queried the laboratory database for patients age ≥18 with a pathology sample for “bone marrow biopsy” with location “iliac crest.” Patient characteristics were limited to those available from the pathology request request forms for each case including: age, sex, HIV status, details on history and laboratory findings. Diagnoses were made by routine care and recorded in the laboratory information system database (LIS), completed by the provider during the biopsy. Descriptive statistics were conducted in R. RESULTS 498 participants were identified; 273(55%) were male with median age of 41 (range 18-82). 305(61%) were HIV negative, 131(26%) HIV positive, and 62(12%) HIV unknown. Specimens collected and analyzed were either trephine and aspirates or both. Of the 498, 283(57%) were trephines, 88(18%) were aspirates and 127(25%) were both trephine and aspirate. Quality of biopsies was excellent, as only 29(6%) were sub-optimal or un-interpretable. Biopsy indications included unexplained anemia 40(8%), cancer staging 29(6%), pancytopenia 8(2%), lymphadenopathy 8(2%), and splenomegaly 5(1%). Indication was not given for 377(76%). The most common diagnosis was benign or reactive bone marrow (i.e., non-malignant) 275(60%). Other diagnoses included ALL 27(6%), AML 19(4%), Benign lesions-NOS 18(4%), DLBCL 16(4%), Aplastic anemias 11(2%), CLL 10(2%), Multiple myeloma 10(2%), MDS 8(2%), CML 8(2%), Carcinomas 8(2%), Hodgkin lymphoma 5(1%), HIV-infection 4(0.9%) among others. CONCLUSION Quality of bone marrow biopsies done under routine care is good in Malawi. However, the most common diagnosis in this population was a reactive bone marrow, for which the underlying cause was not evident to the treating provider. Therefore, further research is needed on the causes of cytopenia in this population.