How do you manage a pituitary adenoma?

Management of Pituitary Adenomas: A Comprehensive Approach

The management of pituitary adenomas requires a multidisciplinary team approach with specialists from both pediatric and adult practice, with treatment decisions based on adenoma type, size, and patient-specific factors. 1

Initial Evaluation

• MRI with contrast is the imaging modality of choice for detailed anatomical delineation of the adenoma 2
• Visual assessment, including visual acuity, visual fields, and fundoscopy, should be performed in all patients with pituitary macroadenoma 2
• All patients with pituitary tumors should be evaluated for gonadal, thyroid and adrenal function as well as prolactin and growth hormone secretion 3
• Genetic assessment should be offered to all patients to inform management and family surveillance, particularly important in children and young people (CYP) who have a higher likelihood of underlying genetic disease 1, 2

Treatment Approach Based on Adenoma Type

Prolactinomas (Most Common Type)

• First-line treatment is medical therapy with dopamine agonists (bromocriptine or cabergoline), even for macroadenomas with visual compromise 2, 4
• Dopamine agonists can achieve tumor shrinkage and normalize prolactin levels in most patients 3, 5
• Surgery is reserved for patients who are resistant to or intolerant of medical therapy 5

Growth Hormone-Secreting Adenomas

• Transsphenoidal surgery is the first-line therapy except for giant macroadenomas or when surgery is contraindicated 6, 3
• Somatostatin analogs are used when surgery is contraindicated, has failed to normalize GH levels, or while waiting for the effects of radiation therapy 3
• Pegvisomant (GH-receptor antagonist) is indicated for patients resistant to somatostatin analogs 3

ACTH-Secreting Adenomas (Cushing's Disease)

• Primary therapy is transsphenoidal surgery by a skilled surgeon, regardless of whether a microadenoma is visible on MRI 3, 4
• Radiotherapy is reserved for patients with subtotal resection or persistent hypersecretion after surgery 3
• Medical therapy with adrenal steroidogenesis inhibitors (mitotane, ketoconazole) may be used while waiting for the effects of radiotherapy 3

Non-Functioning Pituitary Adenomas (NFPAs)

• Treatment should only be offered if the patient is symptomatic, the visual pathway is threatened, or there is interval tumor growth on MRI 2
• Transsphenoidal surgery is the treatment of choice when intervention is needed 1, 2
• For asymptomatic incidental macroadenomas without visual compromise, MRI surveillance may be appropriate 2
• Radiosurgery or radiation therapy is recommended for residual/recurrent NFPAs when the risk of repeat resection is high 1

TSH-Secreting Adenomas (Rare)

• Surgery is the primary treatment 1
• Somatostatin analogs are used if surgery is not curative 5

Surgical Considerations

• Transsphenoidal surgery is the technique of choice, even in patients with incompletely pneumatized sphenoid sinuses 1
• Consider endoscopic rather than microscopic transsphenoidal surgery for potentially superior efficacy in preserving pituitary function 1
• Strict fluid and electrolyte balance monitoring is essential peri-operatively and post-operatively 1, 2
• Common post-operative complications include diabetes insipidus (26%) and SIADH (14%) 1, 2

Post-Treatment Surveillance

• For NFPAs after surgery, MRI surveillance is recommended at 3 and 6 months, and 1,2,3, and 5 years 2, 6
• Visual assessment should be performed within 3 months of first-line therapy 2
• Regular hormone level assessments specific to the tumor type should be conducted during follow-up 2

Special Considerations for Children and Young People

• Pituitary adenomas in CYP tend to have more occult presentation, aggressive behavior, and are more likely to have a genetic basis than in adults 1
• CYP with pituitary adenomas should be treated by a pituitary-specific multidisciplinary team with experts from both pediatric and adult practice 1
• In CYP, there is a greater proportion of functioning tumors, including macroprolactinomas, compared to adults 1
• Collaboration between pediatric and adult specialists is key for optimizing management, transition, and lifelong care 1

Treatment of Residual or Recurrent Adenomas

• Repeat resection is recommended for symptomatic recurrent or residual NFPAs 1
• Radiosurgery with single-session doses of ≥12 Gy or radiation therapy with fractionated doses of 45 to 54 Gy is recommended for greater local tumor control rate of ≥90% at 5 years after treatment 1
• Assessment of NFPA proliferative index and adrenocorticotropic hormone staining can provide guidance on the risk of adenoma progression and the benefit of earlier adjuvant radiation 1

Common Pitfalls and Caveats

• The expertise of the pituitary surgeon significantly influences outcomes, highlighting the importance of treatment at centers with experienced neurosurgeons 6
• Natural history studies of untreated NFPAs show tumor progression in 40-50% of patients, with 21-28.5% eventually requiring surgery 6
• For giant pituitary adenomas (comprising about 6-10% of all pituitary tumors), a multimodal approach involving different therapies in a combined or sequential way is often necessary 7