Endocrine Abstracts

Crooke Cell Adenoma (CCA) is a rare variant of ACTH-secreting corticotroph adenoma. Its importance derives from its aggressive behaviour, association with Cushings Disease and differentiation from metastatic carcinoma. A sixty-year old shopkeeper presented with a two-year history of generalised aches and pains, proximal muscle weakness, increased facial hair and easy bruising. She had also noticed an increased abdominal girth and facial rotundity. There was an eight-year history of Type II Diabetes Mellitus for which she was on maximum doses of metformin and gliclazide. Physical examination revealed a plethoric appearance, soft downy facial hair, a dorsal fat pad without supraclavicular fullness, elevated blood pressure(170/96mmHg) and generalised proximal muscle weakness all consistent with Cushings Syndrome. Overnight dexamethasone suppression test (1mg) yielded a morning cortisol of 580nmol/l. Low dose dexamethasone suppression test (0.5mg QDS) yielded a cortisol of 300nmol/l consistent with a diagnosis of Cushings Syndrome. High dose dexamethasone (2g QDS) suppressed cortisol to 89nmol/l denoting hypercortisolemia of pituitary origin. MRI revealed a 9 millimeter pituitary mass extending into the sellar floor. Optic chiasm was intact. Following trans-sphenoidal hypophysectomy, histology revealed faint focal ACTH positivity, (without suppression of ACTH in adjacent normal pituitary tissue), multinucleated pleomorphic cells, consistent with a diagnosis of the rare corticotroph-variant Crooke Cell Adenoma (CCA). In single isolated reports (submissions to meetings-unpublished) CCA are associated with aggressive behavioural characteristics which emphasises the need for extreme post-operative vigilance.