Pituitary adenomas account for approximately 15% of intracranial tumors. Management of these benign tumors requires diagnosis of the specific intrasellar disease and comprehensive, multidisciplinary treatment of local mass effects and peripheral endocrinopathies. Since tumors can produce different hormones, their consequences and management vary widely.
Testing to Diagnose Hormone-Secreting Pituitary Tumors
| Tumor or Disease | Test | Results Requiring Further Evaluation |
| Prolactinoma | Serum prolactin level measurement | Prolactin level elevated |
| Acromegaly | Serum insulin-like growth factor 1 (IGF-1) level | Age-adjusted IGF-1 level elevated |
| Oral glucose-tolerance test (75 g of glucose) with growth hormone measured at 0, 30, and 60 min | Growth hormone level >0.4 μg/liter with the use of an ultrasensitive assay | |
| Cushing’s disease | 24-hr urinary free cortisol measurement | Elevated urinary free cortisol level on at least two tests |
| Midnight salivary cortisol measurement | Elevated free salivary cortisol level | |
| Plasma cortisol measurement at 8 a.m., after administration of dexamethasone (1 mg) at 11 p.m. | Failure to suppress cortisol level to <1.8 μg/dl | |
| Serum corticotropin measurement | Low corticotropin level suggests adrenal adenoma; very high level may indicate ectopic corticotropin source | |
| Thyrotropin-secreting tumor | Serum thyrotropin measurement, free T4 measurement | Normal or increased free T4 level with measurable thyrotropin may suggest thyrotropin-secreting tumor |
References:
- Melmed S. Pituitary-Tumor Endocrinopathies. N Engl J Med. 2020;382(10):937‐950. [Medline]
- Borg A, Jaunmuktane Z, Dorward N. Tumors of the Neurohypophysis: One Unit’s Experience and Literature Review. World Neurosurg. 2020;134:e968‐e978. [Medline]
Created May 15, 2020.
