Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) Associated with Mediastinal Schwannoma

다국어 초록 (Multilingual 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 102 mmol/L, serum osmolality of 221 mOsm/kg, urine osmolality of 382 mOsm/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.

참고문헌 (Reference)

1 Aughenbaugh GL, "Thoracic manifestations of neurocutaneous diseases" 22 : 741-756, 1984

2 Khanlou H, "Schwannoma of posterior mediastinum: a case report and concise review" 27 : 344-347, 1998

3 Strollo DC, "Primary mediastinal tumors: part II. Tumors of the middle and posterior mediastinum" 112 : 1344-1357, 1997

4 Gale AW, "Neurogenic tumors of the mediastinum" 17 : 434-443, 1974

5 Marchevsky AM, "Mediastinal tumors of peripheral nervous system origin" 16 : 65-78, 1999

6 Ingels GW, "Malignant schwannomas of the mediastinum. Report of two cases and review of the literature" 27 : 1190-1201, 1971

7 Verbalis JG, "Diagnosis, evaluation, and treatment of hyponatremia: expert panel recommendations" 126 : S1-S42, 2013

8 Ellison DH, "Clinical practice. The syndrome of inappropriate antidiuresis" 356 : 2064-2072, 2007

9 Spasovski G, "Clinical practice guideline on diagnosis and treatment of hyponatraemia" 170 : G1-G47, 2014

10 Koch CA, "Clinical aspects of changes in water and sodium homeostasis in the elderly" 18 : 49-66, 2017

11 Anpalahan M, "Chronic idiopathic hyponatremia in older people due to syndrome of inappropriate antidiuretic hormone secretion (SIADH) possibly related to aging" 49 : 788-792, 2001

12 Miller M, "Apparent idiopathic hyponatremia in an ambulatory geriatric population" 44 : 404-408, 1996

13 Pitale SU, "An unusual pituitary mass presenting with panhypopituitarism and hyponatraemia" 77 : 530-531, 2001

14 김응래, "A Recurrent Cellular Schwannoma" 대한흉부외과학회 47 (47): 487-490, 2014

15 Bernreuther C, "A 61-year-old man with hyponatremia" 18 : 283-287, 2008