Introduction: Mass in the suprasellar region could be due to a variety of causes including those of a neoplastic, vascular, congenital, infective or inflammatory origin (1). We report a case of suprasellar mass of likely metastatic origin which was associated with panhypopituitarism and central diabetes insipidus.

Case description: We present the case of a 72 year old gentleman who had recurrent presentations over 3 months with nausea and vomiting, associated with polyuria and significant postural drop. Biochemical testing confirmed panhypopituitarism with predominant severe secondary adrenal insufficiency, and central diabetes insipidus. MRI brain showed a 17mm suprasellar mass. Further investigations revealed a 10mm lesion in the right lung apex with hilar and mediastinal lymphadenopathy on CT chest. Poorly differentiated metastatic adenocarcinoma was confirmed from mediastinoscopy and lymph node biopsy. PET scan confirmed a lung primary with secondary mediastinal lymphadenopathy, but raised the possibility of the suprasellar lesion being a meningioma rather than a metastatic lesion. However the patient had rapid deterioration in his clinical condition with increasing confusion, headaches and behavioural changes. Although he was unfit for brain biopsy, the suprasellar mass was thought to be metastatic due to significant increase in size on repeat MRI associated with clinical deterioration. He has received palliative cranial radiotherapy, but has been deemed unfit for chemotherapy.

Discussion: Suprasellar metastasis is very uncommon (1-2% of all sellar masses) (2) and often has a delayed diagnosis. Common presentations are with headache, visual field deficits, diabetes insipidus and anterior hypopituitarism (3). Surgery is often with a transphenoidal approach. Radiotherapy has been used to control tumour extension either postoperatively or instead of surgery. Chemotherapy has also been used as adjuvant. Prognosis is generally poor with a mean survival of 6 months (4).

References:
1. Hershey BL. Suprasellar masses: diagnosis and differential diagnosis. Seminars in Ultrasound, CT and MR. 1993 Jun;14(3):215-31
2. Gsponer J, De Tribolet N, Déruaz JP, et al. Diagnosis, treatment, and outcome of pituitary tumors and other abnormal intrasellar masses. Retrospective analysis of 353 patients. Medicine (Baltimore) 1999; 78:236
3. Valassi E, Biller BMK, Klibanski A, et al. Clinical features of non-pituitary sellar lesions in a large surgical series. Clinical Endocrinology. 2010 December; 73(6): 798–807
4. Morita A, Meyer FB, Laws ER Jr. Symptomatic pituitary metastases. Journal of Neurosurgery 1998; 89:69