Is It Prudent to Screen the Thyroid before Initiating Treatment for Acromegaly?

Aim: To present a case of acromegaly with coexisting thyrotoxicosis and to emphasize the relevance of screening the screening the thyroid before initiating treatment for thyrotoxicosis.

Presentation of the Case: A 55-year-old lady presented with palpitations, and weight loss of two months’ duration. She also noted her fingers and toes had swollen up, inability to incise properly since two years. Upon examination, she had morphological features clinically diagnostic of acromegaly. Her thyroid was enlarged was on investigation found to have biochemical evidence of thyrotoxicosis. Fine needle aspiration cytology of the thyroid yielded colloid goiter. Insulin like growth factor-1 was elevated. Serum growth hormone after an oral glucose tolerance test was elevated. Magnetic resonant imaging (MRI) of the brain revealed a hypo enhancing focal lesion of size 11X10X12 mm at the pituitary region with delayed contrast enhancement suggestive of pituitary adenoma. Patient was started on anti-thyroid medications and referred to higher centre, and is awaiting surgery for pituitary adenoma.

Discussion: Among patients with acromegaly the incidence of thyroid diseases is around 78% and it has the most common presentation being nodular thyroid disease as the initial presentation. It is uncommon to see patients presenting with symptoms of thyrotoxicosis initially, who had florid morphological features of acromegaly. The prevalence of toxic nodular goiter to the tune of 14.3% in acromegaly. Goiters seen in acromegaly were euthyroid or autonomous, are due to the elevated growth hormone levels independent of TSH action. In about 13 to 17%, thyroidectomies were performed before acromegaly was diagnosed. When patients with acromegaly presents with a weight loss should arouse the possibilities of thyroid cancer or hyperthyroidism.

Conclusion: Screening the thyroid is important, as inadvertent thyroidectomies were performed before acromegaly was diagnosed. When acromegaly co-exists with thyroid dysfunction, the burden of cardiovascular abnormality should be addressed especially, to reduce the morbidity and mortality rate.