Acromegaly: Clinical Perspectives
A 27-year-old male, presented with an episode of generalized tonic clonic seizures, altered sensorium, and rapid breathing. He was diagnosed to have diabetes mellitus about 6 months back and despite being on insulin had poor glycemic control. He had no family history of diabetes. There was history of acral enlargement for the past 8 years. He complained of intermittent episodes of headache, but did not have any visual disturbances. On examination, he was dehydrated, had a blood pressure of 100/60 mm of Hg, and was tachypneic. He had florid manifestations of acromegaly and had no goiter. There was diffuse hyperpigmentation. Although he was dehydrated, he had hyperhidrosis and seborrhea. At presentation, blood glucose was 550 mg/dl, HbA1c 17%, serum β-hydroxybutyrate 6.1 mmol/l, and arterial blood gas analysis revealed high anion gap metabolic acidosis. He was treated with intravenous saline and insulin infusion, with an insulin requirement around 200 units per day. Diabetic ketoacidosis gradually resolved, and he was switched to basal-bolus regimen with an insulin requirement of 100 units per day. His height was 176 cm and weight 80 kg with a BMI of 25.8 kg/m2. Serum electrolytes, calcium profile, and renal and liver function tests were normal. Hormonal workup showed T4 3.5 μg/dl (4.8–12.7), TSH 1.2 μIU/ml (0.27–4.2), 0800 h cortisol 592.6 nmol/L (171–536), ACTH 35 pg/ml (5–60), 0800 h serum cortisol after 1 mg dexamethasone 40 nmol/L (<50), prolactin 17.9 ng/ml (4.0–15), and testosterone 1.3 nmol/L (9.9–27.8). Serum insulin like growth factor 1 (IGF1) was 769.6 ng/ml (116–358), and growth hormone (GH) following glucose tolerance test was 120 ng/ml (<1 ng/ml). MR imaging showed a sellar–suprasellar mass of 4.8 × 3.2 × 3.5 cm abutting the optic chiasm, and his visual field examination confirmed bitemporal hemianopia. He was diagnosed as acromegaly due to macrosomatotropinoma, with secondary diabetes, diabetic ketoacidosis, secondary hypothyroidism, and hypogonadism. Genetic analysis for MEN1 and familial isolated pituitary adenoma (FIPA) was negative. He was started on levothyroxine and testosterone replacement therapy. He underwent transsphenoidal pituitary surgery uneventfully. He did not have CSF rhinorrhea, but had polyuria which resolved after 3 days. Postoperative day 2 serum GH was 4 ng/ml and cortisol was 450 nmol/L. His insulin requirement reduced substantially to 50 units per day. At 3 months he was reevaluated and had a serum IGF1 450 ng/ml and GH 3 ng/ml following glucose load suggestive of residual functioning somatotropinoma. Serum T4 was 7.4 μg/dl and testosterone 7.0 nmol/L on levothyroxine and testosterone replacement and 0800 h cortisol 400 nmol/L. MR imaging showed a residual adenoma of size 1.2 × 1.1 × 0.8 cm, and he is planned for ϒ-knife therapy.
KeywordsGrowth Hormone Fibrous Dysplasia Diabetic Ketoacidosis Pituitary Apoplexy Growth Hormone Excess
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