Bone marrow evaluation in neuroblastomas: bone marrow aspirates have little additional value over trephine biopsies

Bone marrow involvement is essential for staging, treatment evaluation, and progression/relapse detection in neuroblastoma patients. We investigated the diagnostic accuracy of trephine biopsies (TBs) and the additional value of bone marrow aspirate (BMA) cytomorphology, considering clinical implications.

Data were collected from patients diagnosed at our centre over a seven-year period. Complete bone marrow evaluation (bilateral TBs and BMAs) was performed at diagnosis and at predefined timepoints. Cohen's kappa was used to compare test results. Representativeness was assessed for each TB and BMA and the presence or absence of tumour infiltration was reported.

In total, 197 neuroblastoma patients underwent bone marrow evaluation, yielding 1880 biopsies (947 procedures) and 1856 aspirates (934 procedures). TBs were representative in 94.9%, BMAs in 76.8% and complete bone marrow evaluation in 98.4%. Bone marrow infiltration was reported in 40.1%. TBs reported infiltration in 35.5% and BMAs in 19.7%. There was almost perfect agreement between TBs and complete evaluation (κ = 0.901, p < 0.001).

TBs showed higher sensitivity and representativity than BMA cytomorphology. In 4.6% of procedures, BMAs were positive while TBs were negative, but this never led to treatment alteration. These findings suggest that bilateral TBs alone may be sufficient to detect bone marrow involvement.