Case Report: A Striking presentation of a Rare Invasive and Aggressive co- secreting Growth Hormone and ACTH Pituitary Macroadenoma
R Banatwalla, V Horden, D Russell-Jones, Royal Surrey County Hospital
Introduction: Highly invasive Pituitary tumours are rare and represent difficult management problems. Co-secreting tumours are rare, and we report a case exhibiting both features.
Case: 47-year-old gentleman, working as a flight attendant became aware that his peripheral vision was not normal in 2006. The formal visual fields testing reported bitemporal hemianopia and MRI pituitary scan reported a large pituitary mass extending upwards and stretching the optic chiasm. The only symptom he had slight lack of libido. There were no clinical and biochemical signs suggestive of any endocrine syndrome at presentation. He underwent an uneventful Transsphenoidal Hypophysectomy in 2006. The histology was unusual and revealed co-secretion of both ACTH and GH with two separate populations of secretary granules within each cell on electron microscopy1. Post-operatively he did make good recovery, but he required hydrocortisone replacement. Serial imaging revealed a steady growth of his pituitary tumour leading to further surgeries in 2007 and 2014, which was complicated by a post -operative CSF leak. He underwent stereotactic radiotherapy in 2009 and 2016. In 2018, he developed florid Cushings confirmed on biochemical testing. Medical treatment was started, and bilateral adrenalectomy was performed with resolution of the Cushingoid state. His pituitary tumour continued to grow with symptoms of facial numbness and headache presumably due to cavernous sinus invasion.
Treatment options are now limited. Should he be commenced on Temozolomide or Octreotide or should undergo stereotactic radiotherapy be considered for the pituitary tumour invading the skull base (Pituitary bed has received maximum allowable radiation dose).
Discussion: This unusual tumour has demonstrated to co-secrete GH and ACTH that initially presented as a silent adenoma has proven to be resistant to treatment and transformed into a highly metabolically reactive tumour.