Endocrine Abstracts

We are a presenting a 57 year old male victim of recurrent metastatic melanoma who was treated surgically in 2015 by wide local excision together with right axillary dissection for axillary nodal spread. He re-presented to dermatology clinic in December 2018 with skin lesion that was histologically proven to be a BRAF-mutant malignant melanoma. CT scans at that time showed spread to mediastinal and hilar nodes. Oncology team decided to commence Iplimumab/Nivolumab combination therapy for four cycles, three weeks apart, followed by two-weekly Nivolumab maintenance. After the fourth combination dose, he started to suffer from continuous deep-seated progressive headache along with severe fatigue particularly towards mid-day, cold intolerance and poor libido. He denied polyuria or any visual symptoms. Anterior pituitary profile confirmed hypopituitarism with a morning cortisol of 17 nmol/l, TSH of 0.05 mu/l and testosterone of 0.5 nmol/l. He was immediately started on hydrocortisone replacement 10-5-5 mg and levothyroxine 125 mcg daily. Regarding headaches, urgent MRI was done and showed generalised enlargement of the pituitary gland with a central domed component extending up out of the pituitary fossa which is distorting the underside of the chiasm which was bowed superiorly as a consequence. Thus, a three-day course of intravenous methylprednisolone acetate was commenced at a dose of 1 mg/kg per day on an ambulatory care setting along with an urgent visual field assessment that came back normal. The patient was then weaned down to prednisolone 40 mg daily and then was gradually weaned off over several weeks to 5 mg daily. MRI scan was repeated after 4 weeks of methylprednisolone doses and it showed complete resolution of the previous robust radiological findings. The patient reported marked clinical improvement as well. Now six months after the initial diagnosis, the patient is almost asymptomatic and in clinical remission in regards to the melanoma. However, he is still hypopituitary requiring regular replacement of Hydrocortisone 10-5-5 mgs, Leveothyroxine 125 mcg per day and Nebido 1 g intramuscularly every twelve weeks. His most recent morning cortisol (24 h off-hydrocortisone) is 40 nmol/l with a normal thyroid profile and pre-Nebido testosterone level of 12 nmol/l.

Conclusion: Intravenous methyl-prednisolone might have helped to reduced inflammation and pituitary gland size in immunotherapy-induced hypophysitis but still failed to restore eu-pituitarism in this patient after 6 months.

For discussion: 1. Role of intravenous methyl-prednisolone in immunotherapy-induced hypophysitis.

2. Role of routine MRI in these patients.