Bone marrow necrosis (BMN) is an entity that necrotic cells are seen on amorphous eosinophilic ground with medullary infarctus but withouth cortical bone involvement. BMN is a postmortem diagnosis in most of the reports. Bone marrow biopsy and aspiration is essential for the diagnosis. The case we report here is a patient who is diagnosed BMN and ALL at the same time with the first bone marrow biopsy, which is showed extensive necrosis.

A 42-year-old man applied to our E.R. with lumbal pain. The initial blood count showed leukocyte:5.13 × 109/l, neutrophil:2.68 × 109/l, Hgb:10.7  g/dl, Hct: %31.5, thrombocyte:127 × 109/l, LDH:539 u/l (N:0-250), ALP:185 u/l (N:40-150), Total Bilirubin:0.81 mg/dl, CRP:337mg/l (N<5) ), ESH: 94mm/h, folic acide: 2.8ng/ml (N>5.4), Vitamin B12:398 pg/ml (N:210-900), ferritin: 5607 ug/l (N:22-320), fibrinogen:1304 mg/dl (N:200-400), D-Dimer:646 ug/l (N<243) and a normal range for PZ, aPTZ, INR.

Peripheral smear showed %38 PMN, %56 lymphocyte, %6 monocyte, normoblasts, rare tear drop cells and rare thrombocytes. Pathological evaluation revealed hypercellular bone marrow (%95), extensive necrosis, CD3(-) CD5(-) CD20(+), CD38(-), CD10 diffuse(+), BCL2(+) MPO(-) CD117(-), CD34(+) CD79a, Pax5 and TdT suboptimal (+). Flow cytometry showed no significant result because of the deficiency of material. PCR revealed no BCR-ABL transcript.

The patient diagnosed B precursor ALL. With the BFM IA protocol complete remission obtained. At the control BMB CD3, CD20, CD79a, Pax5, TdT, MPO, CD34 was applied but there was no neoplastic involvement. After the BFM IB protocol, complete remission has been pursued. The patient is currently receiving the BFM IC protocol.

BMN is an uncommon pathology with poor prognosis. Primary etiology is malignancies, especially hematologic malignancies, at %90 of the cases. As we see at this case, while the clinical and laboratory findings are insignificant; when a patient shows fever with unknown origin, bone pain, newly developed cytopenias, we must keep in mind the diagnosis of BMN and if a patient is diagnosed BMN, necessary scaning must be done immediately for malignancies as the primary cause.