Endocrine Abstracts

A 50 year old male presented with left visual field loss, afferent pupillary defect and reduced libido in 1999. Initial pituitary profile showed prolactin 130 000 mu/l (55.4–276), and testosterone was 5 nmol/l (10–27.6). MRI pituitary showed giant pituitary macroadenoma compressing chiasm. He was started on Cabergoline with subsequent improvement in visual fields, prolactin levels and size of adenoma on subsequent MRI. His disease remained stable on low dose cabergoline until 2003 when his follow-up MR showed some increase in size of adenoma. His cabergoline dose was increased and his follow-up MR showed stable appearances until 2007 when he presented with horizontal diplopia, and right sixth nerve palsy. MR showed progression in the size of adenoma with cavernous sinus invasion and erosion of floor of pituitary fossa. He was given Radiotherapy along with cabergoline treatment. His tumour size remained stable with some improvement in his prolactin levels. In 2010, he presented again with right ptosis, cranial nerve III and VI palsy, rising prolactin and growing pituitary macroadenoma. Treatment with Quinagolide initiated with no clinical response and later Trans-sphenoidal debulking of tumour was performed. Histology showed high Ki67 (22%) tumour staining for prolactin. He developed partial hypopituitarism and was started on hormone replacements. His tumour increased in size on further MR scan in 2011 with corresponding rise in prolactin. He was treated with six cycles of Temozolamide which resulted in reduction of tumour size and prolactin levels. In 2013, his follow-up MR showed progression in size with rise in prolactin, so he was re-challenged with temozolamide and radiotherapy as surgical intervention was not possible due to tumour invading the cavernous sinus and carotids. In 2015, Transethmoid/Transsphenoid decompression performed in view of further tumour growth and severe headaches on follow-up. MRI showed extensive tumour invasion to right cavernous sinus, Cranial nerve III, IV and VI, right orbital apex, greater wing of sphenoid, Meckel’s cave. Six months later he presented with dysphagia and blurring of vision and MR showed progressive growth of tumour compressing the brain stem. He underwent further surgical Debulking with palliative intent and post-operatively developed hydrocephalus requiring VP shunt.

Discussion points:

i) Is this a malignant pituitary tumour?

ii) What are other treatment options given the resistance to DA and multi-model treatment?

iii) Shall we continue with Cabergoline?