POMC and neoplasm: Compared to those with persistent disease, patients with initial remission had smaller maximal tumour diameter (3.3 ± 2.0 mm vs 15.4 ± 13.0 mm, P = 0.05), lower incidence of cavernous sinus invasion (0% vs 71%, P = 0.03), lower preoperative ACTH (8.4 ± 3.4 pmol/L vs 29.8 ± 10.3 pmol/L, P < 0.01) and lower postoperative MSeC nadir (70.0 ± 45.2 nmol/L vs 408.1 ± 305.3 nmol/L, P = 0.03).