Anterior Mediastinal Neuroblastoma Associated with Syndrome of Inappropriate Antidiuretic Hormone Secretion: A Morphologic, Immunohistochemical, and Genetic Case Report and Review of the Literature.

We report a mediastinal neuroblastoma in an octogenarian with paraneoplastic syndrome of inappropriate antidiuretic hormone secretion (SIADH). Neuroblastomas are very rare tumors in adults, with thoracic or mediastinal locations being especially uncommon. These neoplasms have been occasionally associated with the SIADH. Given the rarity of incidence and paucity of diagnostic and outcomes data, the significance of standard neuroblastoma prognostic characteristics is unclear, and no treatment paradigms exist for these patients. Further studies are needed to inform future clinical guidelines.