title: Idiopathic SIADH in young patients: don't forget the nose.
abstract: Olfactory neuroblastoma (ONB) is an uncommon neuroendocrine sinonasal cancer associated by many authors to ectopic production of several biologically active substances. We report a case of a 31-year-old male patient who presented with idiopathic syndrome of inappropriate secretion of antidiuretic hormone (SIADH). During diagnostic work-up, a CT scan of the head was performed and an ethmoidal ONB was detected. Endoscopical surgery followed by radiotherapy was carried out. Immediately after surgery natraemia levels normalised. Five years later the patient is disease-free. To our knowledge, 17 cases of SIADH associated to ONB have been published. In nine reports, idiopathic SIADH promptly led to the diagnosis of the sinonasal mass as in our clinical case, however, in many reports, correct diagnosis was accomplished months to years later. In young patients with idiopathic inappropriate antidiuretic hormone secretion, a neuroendocrine malignancy of the sinonasal area must be excluded.
authors.affiliation: Institute of Otolaryngology Catholic university of Sacred Heart, Rome, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Parrilla
authors.affiliation: Institute of Otolaryngology Catholic university of Sacred Heart, Rome, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Lucidi
authors.affiliation: Institute of Pathological Anatomy and Cytopathology, Catholic University of Sacred Heart, Rome, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Petrone
authors.affiliation: Institute of Otolaryngology Catholic university of Sacred Heart, Rome, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Bastanza
authors.affiliation: Institute of Radiology, Catholic University of Sacred Heart, Rome, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Colosimo
mesh_terms: D000328:Adult; D018304:Esthesioneuroblastoma, Olfactory / Q000150:complications*; D006801:Humans; D007177:Inappropriate ADH Syndrome / Q000209:etiology*; D008297:Male; D009296:Nasal Cavity; D009669:Nose Neoplasms / Q000150:complications*
keywords: Arginine vasopressin; Olfactory neuroblastoma; Paraneoplastic syndrome; SIADH; Sinonasal