Detection of neuroblastoma in bone marrow by immunocytology: Is a single marrow aspirate adequate?

Background. Except at diagnosis and relapse, when gross disease is present, histologic evaluation is less sensitive than immunocytology (IC) of bone m arrow for detecting metastatic neuroblastoma. We examined whether the chanc e of a positive IC from a single marrow site was comparable to an IC of poo led marrow from multiple sites. Procedure. We carried out 47 marrow examina tions on 29 patients with high-risk neuroblastoma on therapy. Each examinat ion consisted of histologic evaluation of four aspirates and two biopsies ( six sites), IC of a 2.5-5-mL heparinized sample from a single site (the rig ht posterior iliac crest; IC-RPIC), as well as IC of 8-10 mL of heparinized marrow pooled from bilateral anterior and bilateral posterior iliac crests (LC-pooled). IC was performed using a panel of monoclonal antibodies speci fic for ganglioside G(D2). Results. The number of G(D2)-positive tumor cell s detected by IC-pooled had a strong linear correlation with that by IC-RPI C (R = 0.91), although IC-pooled detected an average of 3.3 times more G(D2 )-positive cells. Of 47 examinations, 15 tested positive by histology (6 si tes), 20 by IC- pooled, and 17 by IC-RPIC. Among 29 patients, the level of agreement between IC-RPIC and IC-pooled was generally good (kappa statistic greater than or equal to 0.72), giving a false negative rate of less than or equal to 30%. Conclusions. Compared to conventional histologic examinati ons, immunocytology of a single marrow aspirate generally agrees with that of marrow pooled from six sites. However, the false negative rate may be to o high in the setting of examination prior to bone marrow or stem cell harv est. Med. Pediatr. Oncol. 32:84-87, 1999. (C) 1999 Wiley-Liss, Inc.