We report on the efficacy of the long-acting
somatostatin analog
octreotide in a 43-yr old woman with
ectopic ACTH syndrome. Plasma
cortisol,
ACTH,
beta-endorphin (beta-END) and urinary free
cortisol (UFC) were elevated (range 743-920 nmol/l, 29.2-49.7 pmol/l, 71.0-84.1 pmol/l, 2117-3119 nmol/day respectively). Ovine CRH (oCRH) and high dose
dexamethasone did not affect
cortisol and
ACTH levels, while UFC significantly decreased after
dexamethasone. Initially radiological investigation failed to localize the
ACTH secreting
tumor.
Ketoconazole was not tolerated. Plasma
cortisol significantly decreased both after single (100 micrograms sc) (baseline 531 nmol/l, nadir 218 nmol/l) and 3-day
octreotide administration (from 810 to 448 nmol/l); plasma
ACTH decreased slightly (from 30.4 to 21.3 pmol/l and from 32.4 to 22.5 pmol/l respectively); UFC decreased from 2616 to 711 nmol/day after the 3-day test. Long-term
octreotide treatment (100 micrograms/8h per 54 weeks) led to clinical and biochemical improvement and recurrence followed
drug withdrawal; no side effects were observed. Six months after
octreotide administration a 2 cm lung mass was detected with CT and MR. Surgery was performed and a bronchial
carcinoid was removed. Immunoreactive
ACTH in the
tumor has been demonstrated by histochemistry. Postoperatively a lasting remission of
Cushing's syndrome was observed without further
therapy.