Endocrine Abstracts

Case History: This is a 73 year old lady with known Type 2 Diabetes Mellitus who presented to Acute Medicine with a 2-week history of diarrhoea and acute confusion on a background of a 4-month history of gradual cognitive and functional decline. She was treated for low-respiratory tract infection with acute kidney injury on a background of age-related functional decline. CT brain was organised.

Investigations: CT Brain: Large enhancing soft tissue dense lesion at skull-base causing bone destruction. Differentials are brain metastasis, chronic sinusitis or chordoma.

MRI Brain: Enhancing skull-base mass centred at the clivus extending into the sphenoid sinus but sparing the pituitary.

CT Chest/abdomen/Pelvis: No evidence of any suspicious lesion

Pituitary Hormone profile: LH <0.3 u/L (15.9–54.0), FSH 1.7 u/L (23–116.3), TSH 0.53 mu/L (0.55–4.78), fT3 2.9 pmol/L (3.5–6.5), fT4 16.9 pmol/L (10–18.7), Prolactin 200 mu/L (60–620), IGF1 8.8 nmol/L (4.6–28.3), Cortisol 1258 nm0 l/L (119–619)ACTH 105 ng/l (0–46).

Results and further Investigations: The patient was started on Levothyroxine 50 microgram OD.

Urinary cortisol 1607 nmol/24 hr (0–146). Overnight dexamethasone suppression test: Cortisol 1373 nmol/L (119–619). She then had potassium 2.6 mmol/L needing IV potassium replacement. Low-dose dexamethasone suppression test: Baseline cortisol: 1274 nmol/L and 48 hr post cortisol: 1864 nmol/L. Skull-base MDT outcome at tertiary centre: Chordoma or Plasmacytoma and patient was to be seen as outpatient. Marked clinical deterioration with pneumonia, hypoxia and worsening in swallow. Nasogastric tube was trialled for feeding and medications, but without much success. Metyrapone was commenced but only minimal doses were given due to administration difficulties. The patient was also having significant epistaxis from the mass invading the skull base bones, further complicating nasogastric tube usage. The patient unfortunately died after being palliated.

Conclusion and points for discussion: The patient did not have any cushingoid features clinically and deteriorated rapidly. She had uncontrolled blood glucose, hypokalaemia, high cortisol and high ACTH, high UFC, non-supressed cortisol with ODST and low dose dexamethasone suppression test and she had a skull base mass with no other primaries. Is this ectopic ACTH from a chordoma or is this an ACTH-dependent pituitary adenoma with an odd presentation? Should we have given Metyrapone earlier? Would an early transfer as an inpatient to neurosurgery change the outcome? This case highlights the difficulties in pursuing endocrinological investigations and administration of drugs in a complicated setting.