Endocrine Abstracts

Aim: To access the efficiency of mulitispine computed tomography (MSCT) in ectopic ACTH-syndrome.

Patients and methods: Five clinical cases (2 female and 3 male cases) with severe hypercortisolism were analyzed, age from 26 to 63 years old.

Results: In all of the 5 cases there were significant reasons to suppose ectopic ACTH-syndrome: rapid development of clinical features (in 4 of 5 cases), loss of lean mass compound with rounded and plethoric face patients, presence of cutaneus hyperpigmentation (in 4 of 5 cases), hypopotassemia (in 3 of 5 cases), loss of muscle strength in all of the cases, increase (2) and high (3) values of ACTH combined with absence of adrenal or pituitary adenoma. Mean values of cortisol in blood were 8 am: 1422±1200 nmol/l, 11 pm: 1198±1270 nmol/l, ACTH 8 am: 168.6±148 pg/ml, ACTH 11 pm=176±174 pg/ml, free cortisol excretion in 24 h urine collection 3177±2471 nmol/l. The results of the functional tests also evidenced to ectopic ACTH-syndrome: negative high dose dexametazone test in 4 of 5 cases, low ACTH response to desmopressine injection (in 4 of 5 cases also). All of the cases were suspicious of ectopic ACTH-syndrome, so the search for the source of glucocorticoid excess was conducted. In all of the cases MSCT enabled to visualize the presence of tumor in lungs tissue from 2.5 to 7 mm in size, while positron emission tomography with FDG-18 which one of the patients previously underwent did not find the tumor.

Histological verification was made after the operation of atypical lobar lung resection. It revealed carcinoid tumor in two cases, mixed and small cell cancer in 3 cases. Immunohistochemical analysis shown positive reaction for ACTH in 30%–80% of tumor cells. Developing adrenal insufficiency in all of the patients confirmed radical effect of surgical treatment.

Conclusions: In absence of persuading evidence for pituitary or adrenal genesis of hypercortisolism, patients with high levels of ACTH should undergo desmopressine test and MSCT. So, MSCT may be defined as one of the prior methods of ACTH-producing tumors topical diagnostics.