Results
During a 10-year period, 3,760 bone marrow samples were evaluated. The
samples were made up of ALL, acute myeloid leukemia (AML), and
neuroblastoma diagnoses at 35% (n=1,298), 9% (n=344), and 2% (n=77),
respectively.
During this time, nine samples (0.24%) in six unique patients, all with
malignancy, were identified to have BMN (Table 1). The mean age was
seven years (11 months - 18 years). Four patients were female and two
were male. One patient had relapsed/refractory B-ALL, one had AML, three
had neuroblastoma, and one had diffuse large B-cell lymphoma (DLBCL).
Eight bone marrow evaluations were performed prior to chemotherapy and
one was performed after reinduction therapy.
Hematologic laboratory findings were obtained from eighth encounters.
The mean hematologic laboratory findings were leukocytes of 6.9 x
109/L (range 0.3-13.3 x 109/L),
hemoglobin of 9.7 g/dL (range 8.3-11.5 g/dL), and platelets of 336 x
109/L (38-667 x 109/L). Severe
neutropenia and thrombocytopenia were evidenced only in the patient with
refractory B-ALL. The patient with AML initially had normal peripheral
blood counts when the first bone marrow sample was obtained, however
with subsequent assessments there was gradual development of leukopenia
and neutropenia. Neither of the patients with leukemia had peripheral
blasts at the time of bone marrow evaluation. All patients with
neuroblastoma had normal blood counts at the time of bone marrow
assessment and the majority had extensive tumor involvement in the
marrow ranging from 60% to >95%. Three of our patients
required repeat bone marrow evaluations due to either an inability to
establish a diagnosis, or a suboptimal initial sample.
In regard to systemic symptoms, all patients had musculoskeletal
symptoms manifested as lower extremity and/or back pain. This was the
most common initial complaint and prompted an expanded workup, with five
of six patients undergoing imaging. Plain radiographs were unremarkable;
however, other imaging modalities including bone scan, magnetic
resonance imaging (MRI), and computed tomography were abnormal
demonstrating increased uptake in the bone marrow of long bones, lytic
lesions and/or sclerotic bone.
Follow up was documented in the electronic records for all patients
treated in our institution. The patient with refractory B-ALL died from
vancomycin-resistant enterococcus sepsis. Four patients are in remission
after chemotherapy treatment (2-5 years) (Table 1). Repeat bone marrow
examinations showed no evidence of necrosis on follow up assessment for
both the AML (end of induction) and neuroblastoma (4-7 months of
treatment) patients.