Fine-needle aspiration of ganglioneuroma, maturing type (a.k.a., "borderline ganglioneuroblastoma") in the mediastinum of a young man: Case report and discussion of classification.

We report a very unusual case of a posterior mediastinal tumor in a young man, which we diagnosed by fine-needle aspiration cytology as most consistent with ganglioneuroma, maturing subtype. The cytopathologic features were interpreted using the classification of neuroblastic tumors as defined by the International Neuroblastoma Pathology Committee. Neuroblastic tumors are peculiar tumors that have capacity for maturation, and hence they present as a spectrum of tumors, ranging from the undifferentiated neuroblastoma, to ganglioneuroblastoma, to the mature version ganglioneuroma. The practicing surgical pathologist or cytopathologist who does not regularly encounter pediatric specimens may experience difficulty interpreting a specimen from one of these tumors. The following case report discusses application of these criteria to cytopathologic diagnosis of these tumors.