Endocrine Abstracts

A 23-year-old Caucasian male was referred to Endocrinology with symptoms spanning over 7 years. He was substantially taller than other members of his family measuring 6’3”. He initially presented to Ophthalmology with preseptal cellulitis and noted to have visual field defects with acromegalic features. His pituitary profile showed GH > 100 mu/l, Total T4 104 nmol/l (normal: 60–140 nmol/l), Prolactin 234 mu/l, cortisol 240 nmol/l with flat GST. There was no Diabetes Mellitus and he was normotensive. OGTT showed unsuppressed GH and MRI revealed a pituitary macroadenoma with suprasellar extension. He was diagnosed with Acromegaly secondary to a pituitary GH-secreting adenoma. He underwent TSS and immunostaining showed a pituitary adenoma positive for GH and prolactin, negative for ACTH, FSH, LH and TSH. Post-operatively, his GH and IGF-1 remained elevated. A comparison of GH day curves showed greater response to Bromocriptine than Octreotide. He was discharged on Cabergoline in addition to hydrocortisone. Three months post-operatively, he underwent external beam radiotherapy as his GH and IGF1 remained elevated. MRI showed reduction in size of the pituitary macroadenoma with a small nubbin of suprasellar extension. He underwent re-do TSS 1 year later; histology again confirming pituitary adenoma with similar IHC. Despite this operation, he continued to have elevated GH and IGF1 three months post-operatively. He commenced Octreotide LAR 30 mg IM monthly alongside Cabergoline. He also received Octreotide s/c prn for management of chronic headaches. This eventually normalised his GH, but IGF1 remained elevated resulting in GH/IGF1 discordance. A trial of Pegvisomont was discontinued due to significant side-effects. A year later, MRI pituitary showed empty sella with only a small amount of enhancing pituitary tissue not suitable for gamma-knife radiosurgery. Genetic testing showed Aryl Hydrocarbon Receptor interacting protein (AIP) mutation. Long term complications: He developed hypertension requiring treatment with three anti-hypertensive agents, as well as T2DM. An echocardiogram showed ventricular hypertrophy, but no other structural abnormality. He developed significant skeletal complications involving cervical and lumbar spine (requiring decompression and laminectomies at the age of 31) as well as hip and knee arthropathy. Post-operative hypopituitarism was managed with hydrocortisone, L-Thyroxine and IM Testosterone. Conclusively, his IGF1 has not normalised, though GH has suppressed to target <1 mg/l (mean GH 0.3 mg/l). The current focus of management relates to screening of several long-term complications associated with acromegaly in particular requesting colonoscopy, DXA scan and assessment of OSA.