Ganglioneuroblastoma displays a level of maturation and differentiation that is intermediate between the highly aggressive neuroblastoma on one hand and the benign tumor ganglioneuroma at the other end. All three entities are related and represent a continuum both at the morphologic level as well as at the level of gene expression. Most ganglioneuroblastomas occur in young children and present as bulky masses in mediastinum or retroperitoneum. The case shown here arose in the posterior mediastinum. Cases in adults and the involvement of adrenal gland are uncommon. The gross appearance of ganglioneuroblastoma is variable and depends upon the subtype and degree of differentiation. They are yellow-tan and homogenous in appearance and have a firmer consistency than neuroblastomas. Calcification is almost always present. Image courtesy of Dr. Jean-Christophe Fournet, Paris, France; humpath.com; Used with permission.