Endocrine Abstracts

About 19 year-old, female, presented with sweating in both arms for many years. The sweating has progressively got worse over the last several years. Occasionally, her feet and lower back can also be affected. They do not tend to occur particularly at night and have no association with alcohol, meals or fasting. Her periods are regular. She does not have any associated symptoms such as headache and visual disturbance.

She has no significant family history. She is a student, who is a non-smoker and consumes alcohol at weekends.

On examination, her hands and feet were sweaty. BP 125/70 mmHg. No prognathism and no other features to suggest acromegaly. She had no skin tags, goitre or macroglossia.

Results: IGF-1 level – 75.6 nmol/l (ref: 35–62), oral glucose tolerance test (OGTT) – nadir growth hormone of 0.06 μg/l, MRI Pituitary - the pituitary gland is enlarged with a convex upper margin and the optic chiasm is not involved. There is an area of slight hypo enhancement within the right side of the gland.

Her case was discussed at the local pituitary MDT. The likely diagnosis is acromegaly, but since there was no clear surgical target lesion on pituitary gland, she was offered somatostatin analogues to alleviate her symptoms and we plan to perform an interval pituitary MRI scan.

This is a rare case of likely acromegaly with discordant results. Dimaraki et al (2002) reported that serial plasma IGF-1 measurements could uncover cases of acromegaly (13% cases) despite a suppressed nadir growth hormone level following a glucose challenge. Therefore, IGF-1 alone may be adequately used to diagnose acromegaly and not to be misled by a negative gold standard OGTT. It is important to diagnose acromegaly early in these patients to bring about improvements in the morbidity and mortality associated with elevated IGF-1 and acromegaly.