Rare tumors II: Adrenocortical tumors, neuroendocrine tumors of the appendix, pheochromocytoma and paraganglioma, pancreatoblastoma and solid pseudopapillary tumors of the pancreas

: Very rare tumors are usually divided into two groups: One includes tumors that are rare among both children and adults; the other one encompasses tumors that frequently occur in adults but are rarely observed in children. In this review, we focus on adrenocortical tumors, neuroendocrine tumors of the appendix, pheochromocytoma and paraganglioma, pancreatoblastoma and solid pseudopapillary tumors of the pancreas, with special attention to the role of surgery as main curative intervention or as part of the multimodal treatment.