Diagnostic and prognostic information obtained on fine-needle aspirates of primary neuroblastic tumors: Proposal for a cytology prognostic score.

BACKGROUND

The use of cytological material for diagnosis and prognosis in patients with neuroblastic tumors is poorly described in the literature.

METHODS

A total of 129 patients with primary neuroblastic tumors underwent sampling with fine-needle aspiration for diagnosis and the evaluation of prognostic parameters. Of these, 125 (97%) were neuroblastomas or ganglioneuroblastomas and 4 (3%) were ganglioneuromas. Cellularity of the smears was assessed, as well as the percentage of neuroblasts versus stroma, maturation (differentiating/mature vs immature cells), the mitosis-karyorrhexis index (MKI), and the number of Homer Wright rosettes. The cytology samples were also analyzed for MYCN amplification, flow cytometric DNA index, and array comparative genomic hybridization.

RESULTS

MYCN was found to be amplified in 35 (27%) cases. Strong correlations with overall survival were found for MYCN amplification in localized stages including IVs (P < .001), the percentage of neuroblasts versus stroma (P < .001), maturation (P = .002), MKI (P < .001), and DNA index (P < .03).

CONCLUSIONS

Poorly differentiated tumors with few stromal components and low numbers of differentiating/mature cells were found to be MYCN amplified. The authors propose a "cytology prognostic score" in which neuroblastomas comprised of predominantly neuroblastic elements with no differentiating cells and an MKI >; 2% are classified as high-risk tumors, regardless of their MYCN amplification status. The use of this proposed score would ensure accurate and optimal diagnostic and prognostic classifications of neuroblastic tumors in cases in which the histological biopsy is absent or inadequate for analysis.