Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) Associated with Mediastinal Schwannoma.
- Author:
Shin Han SONG
1
;
Gyeong Ah SIM
;
Seon Ha BAEK
;
Jang Won SEO
;
Jung Weon SHIM
;
Ja Ryong KOO
Author Information
- Publication Type:Case Report
- Keywords: Hyponatremia; Syndrome of Inappropriate ADH (SIADH) Secretion; Mediastinal schwannoma
- MeSH: Aged; Biopsy; Female; Humans; Hyponatremia; Inappropriate ADH Syndrome; Lung Diseases; Mediastinum; Nausea; Neurilemmoma*; Neuroendocrine Tumors; Osmolar Concentration; Pathology; Plasma; Sodium; Thoracic Surgery, Video-Assisted; Thorax; Vomiting
- From:Electrolytes & Blood Pressure 2017;15(2):42-46
- CountryRepublic of Korea
- Language:English
- Abstract: Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is the most common cause of euvolemic hypo-osmotic hyponatremia. There are several etiologies of SIADH including neuroendocrine tumor, pulmonary disease, infection, trauma, and medications. Here, we report a case of SIADH associated with a schwannoma involving the mediastinum in a 75-year-old woman who presented with nausea, vomiting, and general weakness. Laboratory testing showed hypo-osmolar hyponatremia, with a serum sodium level of 102mmol/L, serum osmolality of 221mOsm/kg, urine osmolality of 382mOsm/kg, urine sodium of 55 mmol/L, and plasma antidiuretic hormone (ADH) of 4.40 pg/mL. Chest computed tomography identified a 1.5-cm-sized solid enhancing nodule in the right lower paratracheal area. A biopsy specimen was obtained by video-assisted thoracoscopic surgery, which was diagnosed on pathology as a schwannoma. The hyponatremia was completely resolved after schwannoma resection and plasma ADH level decreased from 4.40 pg/mL to 0.86 pg/mL. This case highlights the importance of suspecting and identifying the underlying cause of SIADH when faced with refractory or recurrent hyponatremia, and that on possibility is mediastinal schwannoma
