(5.06) A Giant Tumor Unveiled: A Case Report of A Massive Pituitary Adenoma Inducing Early-onset Acromegaly.

Acromegaly is a rare disorder with an incidence of 6-8 per million annually. The mean age at diagnosis is 40-45 years, and the average interval from symptom onset to diagnosis is 12 years. The most common presentations are headaches (60%) and visual symptoms (10%).

Case(s) Description :

A 23-year-old male with carpal tunnel syndrome, presented to the hospital with 1 year of recurrent headaches and 7 months of blurry vision that progressed to peripheral vision loss. Ophthalmologic evaluation showed reduced visual acuity and bilateral peripheral visual filed defects. He reported weight gain, increasing size of fingers, slurred speech due to “tongue twisting”, lip swelling, increasing size of forehead and jaw and low libido. On admission, CT head showed a 6 cm sellar mass extending into the suprasellar region, invading the cavernous sinuses bilaterally and compressing the optic nerves. Hormonal assessment revealed normal TSH and free T4 levels, low ACTH (6.1pg/ml) and cortisol (0.8mcg/dl) levels and mildly elevated prolactin at 19.1 ng/mL. His FSH was low at 1.41 mIU/mL, LH was normal at 0.98 mIU/mL, while total testosterone was undetectable at < 10 ng/dL. The IGF-1 level was elevated at 1165 ng/mL with growth hormone (GH) level of 73.3 ng/mL. He had no prior diagnosis of diabetes with HbA1c of 6.4% however his hospital course was complicated by hyperglycemia with blood glucose levels of 350-400 mg/dL requiring high doses of insulin while on IV dexamethasone. He underwent craniotomy with incomplete resection of the tumor. Post-operative GH was 35.2 ng/mL. His post-operative course was complicated by increased intracranial pressure and right basal ganglia infarct requiring VP shunt. Surgical pathology was positive for GH (sparsely granulated pattern) and GATA-3 with scattered prolactin positivity.

Discussion :

The young age at presentation makes this case atypical for acromegaly. He had classic symptoms of acromegaly and found to have markedly elevated IGF-1 levels. The most common etiology of GH excess is an anterior pituitary adenoma with gonadotropins being commonly affected due to mass compression. Acromegaly in young individuals with significantly elevated IGF-1 levels at the time of diagnosis, tumor size with extensive cavernous sinus involvement, elevated post-operative GH levels, and pathological type of sparsely granulated pattern showing a poor response to medical therapy predict a poor long-term prognosis. Early identification of symptoms and screening for acromegaly could have improved outcomes for this patient by avoiding delay in definitive surgery and possibly avoid long term complications including cardiovascular disease, malignancies, and respiratory disorders.