A Long-Term Follow-Up of 2 Cases of Subclinical Acromegaly

Atypical presentations of acromegaly are rare. We present long-term follow-up of 2 patients with acromegaly who had nonspecific symptoms with elevated growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels but lacked classical clinical features.

The first case was a 34-year-old woman who presented with arthralgias, cognitive slowing, and headaches. An incidental brain magnetic resonance imaging scan showed a cystic pituitary lesion. Laboratory tests performed 2 years after initial presentation showed elevated IGF-1 and GH levels, after which she underwent transsphenoidal surgery and lanreotide treatment for symptom control. The second case was a 78-year-old woman with a history of bipolar disorder in whom brain magnetic resonance imaging revealed a 1.5-cm incidental pituitary macroadenoma. Subsequent screening showed elevated GH and IGF-1 levels. She also had laboratory values consistent with primary hyperparathyroidism. Multiple endocrine neoplasia type-1 was ruled out by history. Following parathyroid surgery, the patient remained eucalcemic. She was started on long-acting octreotide due to reluctance for transsphenoidal surgery. Long-term follow-up of both patients was uneventful.

We recommend the term subclinical acromegaly to refer to such patients. These cases highlight the importance of screening all patients with pituitary lesions using an IGF-1 level regardless of presence of classical symptoms of acromegaly.

On long-term follow-up, subclinical acromegaly after treatment has a relatively benign course without development of associated comorbidities, although additional studies involving large number of patients are needed.