bubble_chart Overview

Pituitary adenoma is a benign tumor that is quite common, occurring in approximately 1 in 100,000 people, with an increasing trend in recent years, particularly among women of childbearing age. According to a report from the Beijing Neurosurgical Institute, pituitary adenomas account for 12.2% of intracranial tumors.

bubble_chart Clinical Manifestations

The pituitary gland is an important endocrine organ that contains several types of endocrine cells and secretes various hormones. If an endocrine cell develops an adenoma, specific clinical manifestations may occur. The details are described as follows:

1. Endocrine manifestations of different types of pituitary adenomas

(1) **Growth hormone-secreting adenoma**: In the early stages, the tumor may be only a few millimeters in size, primarily manifesting as excessive secretion of growth hormone. In juvenile patients, this can lead to accelerated growth, even resulting in gigantism. In adults, it manifests as acromegaly, including facial changes (enlarged forehead, protruding jaw, enlarged nose, thickened lips), thickened fingers, and a sensation of tightness when wearing shoes or hats—often requiring multiple size upgrades or even custom-made items. Some patients may also experience increased appetite, coarse skin and hair, hyperpigmentation, and finger numbness. In severe cases, systemic **lack of strength**, **headache**, **arthralgia**, hypogonadism, **amenorrhea**, infertility, and even diabetes may occur.

(2) **Prolactin-secreting adenoma**: Main manifestations include **amenorrhea**, **milk regurgitation**, and infertility. In severe cases, patients may experience axillary hair loss, pale and delicate skin, increased subcutaneous fat, **lack of strength**, fatigue, **drowsiness**, **headache**, and hypogonadism. In males, symptoms include decreased libido, erectile dysfunction, gynecomastia, sparse facial hair, and, in severe cases, genital atrophy, reduced sperm count, and infertility. Gender transformation is rare.

(3) **Adrenocorticotropic hormone (ACTH)-secreting adenoma**: Clinical features include central **obesity**, moon face, buffalo hump, plethoric appearance, and purple striae on the abdomen and thighs, along with increased fine hair. Severe cases may present with **amenorrhea**, decreased libido, systemic **lack of strength**, and even bedridden status. Some patients may also develop hypertension and diabetes.

(4) **Thyroid-stimulating hormone (TSH)-secreting adenoma**: Rare. Excessive TSH secretion leads to hyperthyroidism, which resolves after tumor removal. Alternatively, hypothyroidism may trigger focal pituitary hyperplasia, gradually developing into an adenoma that can enlarge the sella turcica and compress surrounding tissues.

(5) **Follicle-stimulating hormone (FSH)-secreting adenoma**: Extremely rare, with only isolated reports of hypogonadism, **amenorrhea**, infertility, and reduced sperm count.

(6) **Melanocyte-stimulating hormone (MSH)-secreting adenoma**: Very rare, with only sporadic reports of skin hyperpigmentation without cortisol excess.

(7) **Nonfunctioning adenoma**: Early-stage patients may not notice symptoms until the tumor grows large enough to compress the pituitary, leading to hypopituitarism.

(8) **Malignant pituitary tumor**: Characterized by a short history and rapid progression. The tumor not only compresses pituitary tissue but also invades surrounding structures, causing bone destruction at the sella floor or infiltration into the cavernous sinus, leading to oculomotor or abducens nerve palsy. Occasionally, the tumor may penetrate the sella floor into the sphenoid sinus, with neurological symptoms remaining subtle initially.

2. **Visual disturbances**: Early-stage pituitary adenomas often do not affect vision or visual fields. However, if the tumor grows upward and compresses the optic chiasm, visual field defects may occur, initially affecting the superior temporal quadrant (red vision first). As the tumor enlarges and compression worsens, white vision is also impaired, progressing to bitemporal hemianopia. Without timely treatment, visual field defects may expand further, accompanied by declining vision, potentially leading to total blindness. Since pituitary adenomas are mostly benign, **initial stage [first stage]** symptoms may persist for some time before suddenly worsening. If the tumor is unilateral, it may cause monocular hemianopia or blindness.

3. Other neurological symptoms and signs: If the pituitary tumor grows backward and upward, compressing the pituitary stalk or hypothalamus, it may cause polydipsia and polyuria. If the tumor grows laterally and invades the wall of the cavernous sinus, it may lead to oculomotor or abducens nerve palsy. If the tumor penetrates the diaphragma sellae and grows further upward into the ventral part of the frontal lobe, psychiatric symptoms may occasionally occur. If the tumor grows backward and upward, obstructing the anterior part of the third ventricle and the interventricular foramen, symptoms of increased intracranial pressure such as headache and vomiting may appear. If the tumor grows backward, it may compress the brainstem, leading to unconsciousness, paralysis, or decerebrate rigidity.

bubble_chart Auxiliary Examination

1. Endocrine examination: The application of endocrine radioimmunoassay ultra-micro method to directly measure pituitary growth hormone, prolactin, adrenocorticotropic hormone, thyroid-stimulating hormone, melanocyte-stimulating hormone, follicle-stimulating hormone, luteinizing hormone, etc., is of great help in the early diagnosis of pituitary adenomas.

2. Radiological examination

(1) Sella turcica imaging: This is one of the basic examinations. When the pituitary tumor is very small, the sella turcica may show no changes. As the tumor gradually grows, it can lead to sella turcica enlargement, bone destruction, and erosion of the dorsum sellae.

(2) CT scan: After intravenous contrast enhancement, pituitary adenomas as small as 5mm can be detected. However, visualizing even smaller tumors remains challenging.

bubble_chart Diagnosis

The diagnosis of pituitary adenoma is primarily based on the patient's clinical manifestations, visual and field disturbances, other neurological findings, as well as endocrinological and radiological examinations. Diagnosing typical pituitary adenomas is not difficult. However, in the early stages of pituitary adenomas, when symptoms are not very obvious, diagnosis is not easy and may even go undetected.

bubble_chart Treatment Measures

1. Surgical treatment: mainly includes craniotomy and transsphenoidal surgery.

2. Radiation therapy: It has a certain effect on pituitary adenomas, can control tumor growth, sometimes shrink the tumor, and improve vision and visual fields, but it cannot cure the disease fundamentally.

3. Drug therapy: Bromocriptine is a semi-synthetic ergotamine alkaloid that stimulates dopamine receptors in pituitary cells, reducing the effect of prolactin in the blood. After taking bromocriptine, prolactinomas may shrink, menstruation and ovulation can resume, and pathological lactation can be suppressed. However, bromocriptine cannot cure prolactinomas fundamentally—after discontinuation, the tumor may grow again, and symptoms may reappear. Additionally, bromocriptine can alleviate symptoms in growth hormone-secreting adenomas, but the required dosage is high and the efficacy is poor.