An evidence-based recommendation for a standardized approach to detecting metastatic neuroblastoma in staging bone marrow biopsies

Abstract

Neuroblastoma is a common malignant tumor of childhood. Accurate bone marrow (BM) evaluation for metastatic tumor is essential; however, no standardized pathologic workup exists for staging BMs. We examined the diagnostic yield of various BM components and optimal core biopsy (CB) length as part of developing evidence-based recommendations for BM evaluation. After obtaining IRB approval, 160 BM biopsies from 50 neuroblastoma patients were retrospectively selected. H&E-stained CB and clot sections and Wright-stained aspirates were scored as positive, negative, or indeterminate. Total/trabecular CB lengths were measured using cellSens software and a DP71 camera (Olympus). 76/160 BMs were positive for tumor in any component. Of these, 37 (48.7%) were positive in a single portion of the specimen: 19 CBs, 14 aspirates, and 4 clots. Compared with overall diagnosis, sensitivities were as follows: CB 76.3%; aspirate 67.1%; clot 66.7%; core/aspirate combined 94.7%. Mean total Diagnostic CBs had significantly longer trabecular length than nondiagnostic CBs (6.74 mm vs. 4.03 mm, p =0.006). Positive CBs had longer trabecular space than negative marrows (7.91 mm versus 6.25 mm, p= 0.002). Nearly 50% of our positive specimens showed diagnostic discordance among the various components examined. However, combining CB and aspirate examination improved sensitivity for tumor detection. We therefore recommend bilateral CBs (>1 cm each) and aspirates for optimal evaluation of BM for metastatic neuroblastoma.