Journal of Cytology & Histology

Significance of Cytological Findings of Neuroblastomas: Rosette Arrangement and Neuropil Structure

Abstract

Nobuyuki Fukudome, Fumikazu Kimura, Shigenari Arita, Chamidu Atupelage and Kunio Mizuguchi

Objectives: Improve treatment outcomes and clarify the biological characteristics of neuroblastoma, development of an international histological classification started several years ago. Aiming at the establishment of a cytology criteria corresponding to the new histological classification, we investigated a criteria comparing lesions related to neuroblastoma on referring to the morphological indices of neuroblastoma reported in the international classification.
Methods: Several tumor specimens were investigated: 37 cases of neuroblastoma (undifferentiated type: 3, poorly differentiated type: 34), 3 cases of ganglioneuroblastoma (mixed type: 2, nodular type: 1), and one case of ganglioneuroma. Stamp cytology samples were prepared from cut surfaces of the tumors and then stained to the Papanicolaou method.
Results: In neuroblastoma of the undifferentiated type, tumor cells contained a small oval nucleus with a high N/C ratio, showing a bare nucleus, and the nucleolus was distinct: no rosette formation or neutrophil was observed. In the poorly differentiated type, tumor cells showed a round-oval bare nucleus were scattered: rosette arrangement was observed in the background neuroblasts containing a bare nucleus. In ganglioneuroblastoma, immature neuroblasts showed a round-oval nucleus and large ganglion-like cells possessed a distinct nucleolus similar to poorly differentiated-type epithelial adenocarcinoma.
Conclusion: In neuroblastoma, neutrophils were stained light green, and a partial Homer-Wright-type rosette arrangement was observed in the background. In the poorly differentiated type, tumor cells were generally large compared to those observed in the undifferentiated type. In ganglioneuroblastoma, cytological diagnosis can be relatively easily made when differentiated mature ganglion like cells are observed. In the case of surgery, a histological diagnosis of nervous system tumors is often performed using frozen sections, however tissue is usually damaged during freezing. Thus, cytology is more advantageous for diagnosis. The diagnostic accuracy can be improved utilizing the cytological characteristics of neuroblastic tumors.