Signs and Symptoms of Pituitary Adenoma
Pituitary adenomas present with distinct clinical manifestations that vary based on tumor size, hormone secretion status, and mass effect on surrounding structures. The symptoms can be categorized into three main groups: hormone hypersecretion syndromes, hypopituitarism, and mass effect symptoms 1.
Hormone Hypersecretion Syndromes
Prolactinoma symptoms: Delayed or arrested puberty, growth failure, primary amenorrhea, galactorrhea, menstrual disturbance or secondary amenorrhea in females; hypogonadism, decreased libido, erectile dysfunction, and gynaecomastia in males 1, 2, 3
Growth hormone excess: Gigantism in children, acromegaly in adults (enlargement of lips, tongue, nose, hands, and feet) 2, 3
ACTH-secreting tumors (Cushing disease): Obesity, hypertension, diabetes, and other morbidities related to hypercortisolism 2, 4
TSH-secreting tumors: Hyperthyroidism (rare, accounts for approximately 1% of pituitary adenomas) 2, 4
Mass Effect Symptoms
Headache: Common presenting symptom, especially with macroadenomas (≥10mm) 1, 3
Visual disturbances: Visual field defects (particularly bitemporal hemianopsia), loss of central vision, and decreased visual acuity due to compression of the optic chiasm 1, 3
Cranial nerve palsies: Diplopia and ocular motility problems from compression of cranial nerves III, IV, or VI 1, 3
Pituitary apoplexy: Sudden onset of severe headache, visual impairment, and potential hypopituitarism due to hemorrhage or infarction within the tumor (more common in children than adults) 1
Hypopituitarism
Growth failure or short stature: Due to growth hormone deficiency 1
Delayed or arrested puberty: Secondary to gonadotropin deficiency 1
Hypothyroidism: Fatigue, cold intolerance, weight gain from TSH deficiency 1
Hypocortisolism: Fatigue, weakness, hypotension from ACTH deficiency 1
Central diabetes insipidus: Extremely rare at diagnosis of non-functioning pituitary adenomas unless apoplexy has occurred; presence strongly suggests alternative diagnoses such as craniopharyngioma, histiocytosis, or germ-cell tumor 1
Age and Sex-Specific Presentations
Children and adolescents: More likely to have functioning tumors, particularly macroprolactinomas, and more aggressive disease behavior than adults 1
Prepubertal children: Corticotrophinomas more common than prolactinomas 1
Adolescents: Prolactinomas become more common, with 93% presenting after 12 years of age 1
Sex differences: Pituitary adenomas are 3-4.5 times more common in female than male patients, though non-functioning adenomas show no consistent sex predisposition 1
Males with prolactinomas: Often present later with larger tumors and more pronounced mass effects compared to females 1, 5
Non-Functioning Pituitary Adenomas
Microadenomas: Usually asymptomatic and discovered incidentally on imaging 1
Macroadenomas: Present with mass effects including headache, visual field defects, and hypopituitarism 1
Incidence: Account for 4-6% of pediatric pituitary adenomas but 15-30% of adult pituitary adenomas 1
Age distribution: Usually present in the second decade of life with increasing incidence thereafter 1
Important Clinical Considerations
Visual assessment is critical for any suspected pituitary macroadenoma, as visual deterioration is an urgent indication for surgical decompression 1
Hyperprolactinemia may occur due to stalk compression from macroadenomas (usually below 2,000 mU/l or 94 μg/l) and should be distinguished from true prolactinomas 1
Pituitary incidentalomas (found incidentally on imaging) are becoming more common with increased use of brain imaging 3, 5
Genetic testing should be considered in children and young people with pituitary adenomas due to higher likelihood of underlying genetic disease compared to adults 1
Early diagnosis is crucial as pituitary adenomas can disrupt maturational, visual, intellectual, and developmental processes in children and young people 1