Endocrine Abstracts

Introduction: Silent corticotroph adenomas(SCA) are defined as pituitary adenomas showing positive staining for adrenocorticotrophic hormone in immunohistochemical studies not associated with clinical/laboratory features of hypercortisolaemia. We report a case of SCA in a 61-year-old man, who presented with pituitary apoplexy.

Case presentation: Patient presented with persistent diplopia of 3 months duration, associated with severe headache for 1 week. He had a history of hypertension but no other conditions. On examination a third nerve palsy and ophthalmoplegia in the right eye were observed. He was normotensive and did not have any clinical features of Cushing’s syndrome. MRI Pituitary showed large intrasellar and suprasellar haematoma related to underlying pituitary adenoma extending into the right cavernous sinus, compressing the optic chiasm with features of apoplexy. Biochemistry revealed 9 am cortisol of 247 mmol/l, FT4 10.4 pmol/l, Na 140 mmol/l, K 4.0 mmol/l and HbA1c 5.3%. He was immediately started on hydrocortisone replacement therapy and underwent transsphenoidal hypophysectomy. Post-operatively, right 3^rd nerve palsy resolved and ocular movement improved. Biochemistry showed the following levels:Cortisol 354 nmol/l, FT4 14 pmol/l, TSH 1.14 mIU/l, Testosterone 12.3nmol/l, FSH2.7IU/l, LH4.4IU/l, Prolactin 108, ACTH 5.0 ng/l. Overnight dexamethasone suppression test showed adequate suppression, with cortisol levels of 26 nmol/l.24 hr urine cortisol levels were normal. Histology showed expression of corticotroph cells(Ki-67, 3-5%). Findings were consistent with Grade 2b as per PitNET 2017 classification. Postoperative MRI showed decompression of the chiasm and tiny residual tumour in the right cavernous sinus.

Conclusion: This is an interesting case with a likely pre-existing pituitary macroadenoma, presenting with features of apoplexy, but no obvious triggering factor. Histology revealed a SCA. As per 2017 guidelines he should be monitored closely for potential aggressive behaviour.