Endocrine Abstracts

A 64 year old female presented to A&E with a 3 month history of general decline, low mood and 8 kg weight loss. On examination there was facial plethora, thin skin with generalised bruising and peripheral oedema. Initial blood tests showed raised inflammatory markers, low potassium (2.6 mmol/l) and deranged liver function tests. A CT chest/abdomen/pelvis found a 2 cm lesion in the left lung with extensive liver metastases but no nodal deposits in the abdomen so this was felt to be a lung primary with liver metastases. A liver biopsy showed grade 2 neuroendocrine tumour (NET) with Ki67 3-5%. In the interim the patient went to Germany where she was started on chemotherapy. The patient returned to the UK one month later and presented to A&E with general malaise. She was found to be profoundly hypokalaemic with worsening liver function. A pituitary profile showed secondary hypothyroidism, hyperprolactinaemia and hypogonadotropic hypogonadism. She had a raised ACTH with 9am cortisol of 1350 nmol/lwhich did not suppress on dexamethasone testing. 24 hr urine free cortisol was also raised at 1730 nmol/l. MRI pituitary showed a 11mm mass closely associated with the infundibulum and elevating the chiasm but appeared to be separate from pituitary gland. After discussion in pituitary and NET MDT meetings, she was started on prophylactic rivaroxaban, lanreotide and metyrapone. Functional imaging was carried out which showed that the lung lesion was FDG positive but did not take up Gallium which is unusual for a NET. Two attempts at lung biopsy were unsuccessful and the patient was deemed to be too frail for inferior petrosal sinus sampling. The decision was made to go ahead with medical management to stabilise the patient without confirmation of source of ACTH. She was commenced on metyrapone but was unable to normalise cortisol as she could not tolerate higher doses of metyrapone. An application was approved to use the novel agent Osilodrostat on compassionate grounds. This led to a marked reduction in cortisol levels and she was quickly established on a block and replace regime. She has remained well on osilodrostat therapy for 6 months and has been able to tolerate several cycles of chemotherapy with good effect. We have been monitoring her pituitary lesion which has marginally increased in size and further review in pituitary MDT have concluded that it is most likely to be a pituitary metastasis.