Diagnosis

Pituitary adenoma

Etiology

Cause [f9q]

• Sporadic clonal expansion of mutated cells of unknown cause (95%)

• Specific genes mutations such as MEN, CNC, FIPA (5%)

Pathophysiology [f9q][kog]

• Usually benign and asymptomatic (43%)

• Symptomatic tumors due to:

  • Hormone secretion --> Hormonal excess

  • Hypopituitarism --> Hormonal deficiency

  • Compression of the surrounding tissue:

    • Visual impairment

    • Headache

• Types: [yfp][af1]

  1. Prolactinoma (60-70%): amenorrhea, galactorrhea, gynacomastia

  2. ACTH-secreting adenoma/Cushing disease (6%): obesity

  3. Growth hormone secreting adenoma: gigantism and acromegaly

  4. TSHoma: elevated and unsuppressed TSH --> elevated thyroxine --> secondary hyperthyroidism

  5. Gonadotrophinoma: precocious puberty or ovarian hyperstimulation syndrome

  6. Incidentaloma/Non-functioning adenoma (15%): non-secreting pituitary adenoma

     • Adults: 15–30% of clinically relevant pituitary adenomas and 50–60% of surgical cases

     • Children: 4–6% of all pediatric pituitary adenomas, 10% of surgical cases

Epidemiology

Incidence per 100.000 [tzt][dm5][5mp][f9q][oes][qkh][wot]

Approach

• Prolactinoma: serum prolactin [yfp]

• Cushing disease: plasma ACTH, serum cortisol (midnight), salivary cortisol (late night), 24-h urinary free cortisol, dexamethasone suppression test

• Growth hormone adenoma: IGF-1/GH suppressed after an oral glucose load

• THSoma: TSH, free T4

• Gonadotrophinoma: FSH, LH, β-hCG, testosterone, estrogen, testicular ultrasound

• Incidentaloma/Non-functioning adenoma: exclusion of hormones disturbances

• CT caput

• MRI caput

Treatment

1. Prolactinoma: [yfp]

   1. Dopamine agonist (Cabergoline) --> reduce serum prolactin and induce tumor shrinkage

   2. Surgery if:

      • The patient is unable to tolerate or is resistant to high-dose cabergoline

      • Deteriorating vision on cabergoline

   3. Radiotherapy if surgery is not an option

   4. Consider Temozolomide when resistant to medical, surgical and radiation therapy

2. Cushing disease:

   1. Surgery: Adenomectomy

   2. Radiotherapy if not amenable to curative surgery

   3. Medical therapy with adrenal steroidogenesis inhibitors (metyrapone or ketoconazole) reduce the cortisol burden while awaiting definitive surgery/radiotherapy

   4. Etomidate IV if severe Cushing disease with severe cortisol excess

   5. Bilateral adrenalectomy if severe refractory Cushing disease or for life-threatening emergencies

3. GH-secreting adenoma: gigantism and acromegaly

   • Surgery to reduce GH

   • Consider preoperative medical therapy with somatostatin analogues and/or GH receptor antagonists

   • Radiotherapy if uncontrolled tumor growth and incomplete surgical and medical response

4. TSHoma:

   • Somatostatin analogue to normalize thyroid function

   • Definitive surgery: transsphenoidal resection

   • Radiotherapy if:

     • Tumor remnant

     • Resistance to medical therapy

     • Relapsing TSHomas and re-operation is not an option

5. Gonadotrophinoma:

   • Surgical resection

   • Postoperative remnant or recurrence --> radiotherapy

6. Incidentaloma/Non-functioning adenoma:

   • Transsphenoidal surgery if hypopituitarism or visual disturbances

   • Consider second surgery or radiotherapy

   • MRI surveillance at 3 and 6 months, and 1, 2, 3 and 5 years after surgery

Differential diagnoses

Acromegaly, Adrenal insufficiency, Astrocytoma, Basilar artery thrombosis, Cerebral venous sinus thrombosis, Craniopharyngioma, Cushings disease, Cushing syndrome, Dermoid Cyst, Diabetes mellitus, Ependymoma, Gigantism, Glioblastoma multiforme, Glioma, Hypopituitarism, Hypothyroidism, Lymphoma, Meningioma, Meningitis, Osteoporosis, Polyneuropathy, Prolactinoma