ACTH producing pulmonary carcinoid and pituitary macroadenoma: a fortuitous association?

We report a case of a 45 year-old man who presented initially with a non-functioning pituitary macroadenoma. A routine chest radiography done preoperatively revealed a right lung nodule which was confirmed by computed tomography (CT) of the thorax. Transfrontal hypophysectomy was performed while a conservative approach was taken for the lung nodule. Four years later, he presented acutely with adrenocorticotrophic hormone (ACTH) dependent Cushing's syndrome which resolved following a right lobectomy. Histological examination revealed an atypical carcinoid. To our knowledge, this is the first reported case of an ectopic ACTH secreting pulmonary carcinoid found in association with a non-functioning pituitary macroadenoma.

Masking of central diabetes insipidus and hypogonadotrophic hypogonadism by germ cell tumour in suprasellar--pineal region.

A patient with beta hCG-secreting germ cell carcinoma of the pineal and suprasellar regions presented with hydrocephalus, Parinaud's syndrome, hypopituitarism and polyuria. Central diabetes insipidus was strongly suspected although the water deprivation test was not diagnostic. The polyuria however, responded to ADH analogue when the hypothyroidism and hypocortisolism were treated. Pubertal development was evident and serum testosterone was normal despite the low FSH/LH, suggesting hCG stimulation of Leydig cells. This case illustrates that a beta hCG-germ cell tumour of the suprasellar region causing hypopituitarism can mask the presence of central diabetes insipidus and hypogonadotrophic hypogonadism.

Intraoperative ultrasound with palpation is still superior to intra-arterial calcium stimulation test in localising insulinoma.

AIM: This study assessed the sensitivities of preoperative localisation modalities such as computed tomography (CT), magnetic resonance imaging (MRI), arteriography and arterial stimulation venous sampling (ASVS) using serum insulin and C-peptide gradients to intraoperative techniques in localising insulin-secreting tumours in our institution. METHODS: Fourteen patients with proven insulinoma, aged 20-66 years, who presented from 1997 to 2004, were studied retrospectively. All patients underwent ASVS where C-peptide and/or insulin gradients were calculated. The results were compared with the preoperative findings of CT, MRI, arteriography, as well as intraoperative ultrasound and palpation. RESULTS: Intraoperative ultrasound with palpation correctly localised 10 of the 11 tumours with a sensitivity of 91%. Sensitivities of other localisation techniques were lower: 31% by CT, 50% by MRI, and 46% by arteriography. ASVS with insulin gradients alone allowed accurate localisation in 40% of patients while localisation using only C-peptide gradients of more than 2 was 43%. The insulinomas, measuring 10-30 mm, were successfully removed in 13 patients--6 from the body, 4 from the tail, 2 from the head and 1 from the junction of the body and tail. All except 1 were cured by selective surgery and remained free of hypoglycaemia over the next 2-60 months of follow-up. One patient had left lobectomy due to liver metastases from a malignant insulinoma and remained asymptomatic with medical therapy. CONCLUSIONS: Intraoperative ultrasound with palpation is a highly sensitive method for the localisation of insulinoma compared with other preoperative localisation techniques.