Endocrine Abstracts

Introduction: In children, tumours occupying the pituitary fossa are mainly craniopharyngioma (80–90%) and pituitary adenomas (2–3%). We present two cases of pituitary adenoma and the challenging management when complete surgical resection is not possible. Case 1: A 13.5 year old girl presented with tall stature. Pituitary hormone profile revealed high IGF1 123 nmol/l (24.5–66) and prolactin 722 mU/l (102–496). Growth hormone (GH) was not completely suppressed on the oral glucose tolerance test (nadir 4.5 μg/l). She was in established puberty although no menarche. MRI showed pituitary enlargement with no definite microadenoma. She underwent transsphenoidal pituitary exploration. An adenoma was removed and immunohistochemistry showed GH and prolactin expression in the tumour cells. Post-operatively, GH suppressed to 0.3 μg/l on OGTT. During the following year, IGF-1 rose to 85.4 nmol/l. Repeat MRI revealed bulky pituitary, suggestive of residual tumour. She underwent second transsphenoidal surgery with evidence of TSH, ACTH and gonadotrophin deficiency on follow up with a suppressed GH level of 0.1 μg/l on OGTT and low IGF1 9.8 nmol/l (34.8–64.2). Case 2: An 11.4 year old boy presented with a 6-month history of worsening headaches and an intracranial mass on CT scan. Clinical examination revealed features of gigantism. Hormonal assessment showed grossly elevated random GH – 722 μg/l, and IGF1 at 77.6 nmol/l (11.1–32.3). Rest of anterior pituitary function appeared normal and he was in early puberty. MRI brain showed a large macroadenoma with suprasellar extension. Ophthalmology assessment showed bitemporal superior quadrantanopia. He underwent transsphenoidal debulking. Histopathology confirmed somatotroph adenoma. Post-operatively IGF1 remained elevated and Lanreotide autogel 60mg was commenced with minimal effect on IGF1 levels after 3 months. He underwent further surgery (transcranial) and complete resection proved impossible. Medical treatment intensified with increased dose of Lanreotide without achieving biochemical control. He progresses through puberty with a height velocity of 1.4 cm/yr. Recent MRI showed interval decrease in residual disease. Further management will consist of testosterone (epiphyseal closure), adjuvant Pegvisomant and proton beam radiotherapy.

Conclusion: These cases demonstrate the challenges of managing pituitary adenomas in children particularly when complete surgical resection is not possible and evidence for optimal management in this age group limited.