Endocrine Abstracts

Case History: A 71-year-old man with well controlled hypertension and left eye blindness due to congenital toxoplasma chorioretinitis presented to his GP with worsening headache. Initial CT head revealed a massive left parasellar lesion (32*25*36 mm) with suprasellar extension. Gadolinium-enhanced MRI revealed large cystic sellar mass, marked chiasmal compression and total encasement of Left carotid artery. 48 hours after MRI he was admitted acute severe right abdominal pain. CT abdomen showed right adrenal haemorrhage with possible underlying adrenal mass and diffuse right retroperitoneal hematoma. Clinical assessment did not reveal a Cushingoid phenotype. He had complete visual loss on the left eye (old) with complete oculomotor palsy (sub-acute). Formal ophthalmic assessment confirmed left optic nerve (ON) damage, chorioretinal scarring and mild right ON involvement.

Investigations: Biochemical investigations showed significant ACTH-dependent hypercortisolaemia (9am cortisol >1750 nmol/l, ACTH 1213 ng/l, 24h UFC >1422 nmol/24h) and profound central hypogonadism. The rest of the anterior pituitary profile was normal. Owing to the severity of hypercortisolaemia that persisted over a week, Metyrapone was commenced. There was rapid reduction of cortisol to 563 nmol/l. Metyrapone was stopped within four days of commencement. Cortisol biochemistry improved but did not normalise at four weeks post adrenal haemorrhage; 24h UFC 116nmol/24h (<120), post ODST cortisol 280 nmol/l and ongoing loss of diurnal rhythm.

Treatment: Trans-sphenoidal surgery was undertaken following regional MDT discussion with the primary aim of preserving vision in the right eye. Surgery was uneventful. Histology showed an ACTH staining, densely granulated corticotroph adenoma with Ki67 index of 5%. He had severe biochemical hypercortisolaemia in the early postoperative period (Cortisol >1600 nmol/l and ACTH 376 ng/l) that improved spontaneously 2 weeks later to 601 nmol/l and 253ng/l respectively. Two months later, right adrenal haemorrhage has completely resolved and underlying indeterminate 1.5*1.9 cm mass revealed (HU; precontrast 39, portal 59 and delayed phase 55). He awaited further follow up with close biochemical monitoring and consideration of a stage procedure to achieve further clearance.

Discussion: • This pituitary adenoma appears to represent a whispering/smouldering corticotroph adenoma leading to an exuberant cortisol response to stress. • The size and anatomical extent of the lesion make clearance a difficult undertaking with significant associated risk. • Despite the severe derangement in biochemistry there is no clinical evidence of end organ effects of chronic hypercortisolaemia.