Pituitary tumors are a group of neoplasms originating from the anterior and posterior pituitary glands and the residual epithelial cells of the craniopharyngeal duct, accounting for approximately 10% of intracranial tumors. They can occur at any age but are most common in individuals aged 40 to 50. Classification: 1. Functional (secretory) pituitary tumors, including prolactinomas, growth hormone-secreting adenomas, ACTH-secreting adenomas, Nelson syndrome (ACTH-MSH-secreting adenomas), thyrotropin-secreting adenomas, and mixed adenomas. 2. Nonfunctional (non-secretory) pituitary tumors, also known as "chromophobe adenomas," which account for 20-35% of cases.

bubble_chart Diagnosis

1. Medical History and Symptoms:

Functional pituitary adenomas often present with characteristic clinical symptoms. Even microadenomas (diameter <10mm) can cause hyperfunction, such as excessive growth hormone leading to acromegaly; excessive ACTH causing Cushing's disease; and excessive prolactin resulting in milk regurgitation, amenorrhea, and impotence. Non-functional pituitary adenomas are often discovered when the tumor grows large enough to compress the optic chiasm, pituitary gland, or hypothalamus, leading to symptoms such as headache, visual impairment, visual field defects, amenorrhea, and impotence.

2. Auxiliary Examinations:

(1) Hormone Assays:

Most functional pituitary adenomas secrete a single hormone, and measurements of anterior pituitary hormones and target gland hormones can often provide an early qualitative diagnosis. However, it should be noted:

(1) Baseline pituitary hormone levels are easily influenced by internal/external environments, medications, and circadian rhythms;

(2) In a single pituitary adenoma, elevated blood hormone levels may not be limited to one type. This phenomenon does not necessarily indicate a mixed adenoma unless both hormones are significantly elevated;

(3) Hormone levels may not correlate with tumor size or clinical symptoms, as the latter depend on factors such as disease duration, hormone type, presence of degenerative or cystic changes in the tumor, and other substances affecting hormone activity. Therefore, hormone assays should be repeated multiple times, and hormone stimulation or suppression tests may be necessary.

1. Sella Turcica X-ray: In larger pituitary adenomas, plain films may show an enlarged sella turcica, downward displacement of the sella floor, and bone destruction of the dorsum sellae.

2. Pituitary CT Scan: Can detect microadenomas larger than 3mm in diameter.

3. MRI: Provides highly precise localization of pituitary adenomas.

(3) Visual Field Testing:

Regular visual field testing not only aids in diagnosis but also helps monitor prognosis.

3. Differential Diagnosis:

Pituitary adenomas with an enlarged sella turcica should be distinguished from empty sella syndrome, where the sella turcica shows spherical enlargement without bone destruction, and CT can confirm the diagnosis. Non-functional pituitary adenomas must be differentiated from various parasellar diseases, such as extra-pituitary tumors, inflammation, degeneration, and hemangiomas.

bubble_chart Treatment Measures

Treatment should be based on the nature of the adenoma and its size, employing surgical therapy, radiation therapy, and/or drug therapy.

(1) Surgical Therapy:

Except for prolactinomas, early surgical intervention should be prioritized.

(2) Radiation Therapy:

Suitable for small tumors without erosion or compression of the suprasellar or extrasellar regions, for cases where surgical treatment is ineffective or the patient declines surgery, and as adjuvant radiotherapy post-surgery. In recent years, X-knife and γ-knife stereotactic radiotherapy have been applied.

(3) Drug Therapy:

Bromocriptine (a dopamine agonist) can be used to treat prolactinomas and acromegaly; cyproheptadine (which inhibits serotonin-stimulated CRH) for Cushing's disease; and the somatostatin analog octreotide for acromegaly and TSH-secreting tumors. Alternatively, radiotherapy or drug therapy may be used as adjuvant treatment after surgical resection of the adenoma.