Pituitary Tumors
Pituitary tumors are almost always benign tumors that can be cured.
Causes of pituitary tumor patients with symptoms Chen Ge, Department of Neurosurgery, Xuanwu Hospital, Capital Medical University
Excessive secretion of hormones
Localized occupying effect
Inability of residual normal pituitary tissue to provide adequate hormone levels
Types
Pituitary tumors include the following (in descending order of frequency of occurrence)
Functional adenomas
Prolactinoma
Growth hormone tumors
Adrenocortical hormone tumors
Thyrotropinomas
Luteinizing hormone/follicle stimulating hormone tumors
Hormone production
Common tumors with hormonal activity include mainly eosinophilic growth hormone adenomas, basophilic adrenocorticotropic hormone adenomas and prolactin adenomas. These tumors can grow through the pituitary fossa (pterygoid saddle).
Adrenocorticotropin-type tumors: basophilic adenomas that present as Cushing’s syndrome (Cushing’s syndrome) with slowly increasing tumors. It is initially confined to the pterygoid saddle, but may increase in size or even become invasive after removal of both adrenal glands (Nelson’s syndrome).
Prolactin-type adenoma: It is commonly intra-saddle growth and can be small (less than 10mm) but can also enlarge and enlarge the pterygoid saddle.
Growth hormone-type tumors: eosinophilic, often leading to gigantism in childhood and acromegaly in adults. Suprasellar extension is not uncommon and grows slowly.
Non-functional tumors.
Grows across the pterygoid saddle and compresses surrounding tissue structures to produce symptoms, so it does not exhibit endocrine symptoms. Visual disturbances are a common first presentation.
Epidemiology
The annual incidence of clinically symptomatic pituitary tumors is approximately 1-2 cases per 100,000 population.
Considering some undiagnosed cases, the actual incidence may be higher.
Clinical presentation
Depends on the hormonal type of the tumor and the mode of growth in the saddle.
Focal symptoms due to tumor growth.
Growth in the pituitary fossa can lead to headache, neurological visual field defects or facial pain, depending on the size of the tumor and its direction of growth
Headache: The typical location is posterior to the globe or bilateral temporal, aggravated by walking. Sudden and severe headaches are often caused by pituitary tumor strokes (pituitary tumor hemorrhage). Large pituitary tumors can cause obstruction of the cerebrospinal fluid circulation, leading to hydrocephalus and enlargement of the lateral ventricles.
Visual field defects: common but often unrecognized by the patient. Bilateral temporal hemianopia is the classic presentation, but unilateral or bilateral visual field defects can also occur.
Actinic nerve palsy can lead to strabismus.
Invasion of the hypothalamus often leads to decreased appetite, irritability, abnormal thermoregulation and impaired consciousness.
Early manifestations of pituitary hormone deficiency.
Total pituitary hypoplasia or deficiency of six hormones its momentary occurrence
Hypopituitarism often occurs in the following order: luteinizing hormone (LH), growth hormone (GH), thyrotropin (TSH) and, finally, decreased levels of adrenocorticotropic hormone (ACTH) and follicle-stimulating hormone (FSH).
Common symptoms in adults are infertility, amenorrhea, decreased libido and erectile dysfunction. Luteinizing hormone and growth hormone deficiencies can lead to muscle atrophy, decreased body hair, centripetal obesity and smaller testes.
Hypopituitarism in children often manifests as delayed puberty or growth retardation.
Diabetes mellitus and enuresis are rare symptoms but often occur after pituitary tumor surgery.
Overproduction of pituitary hormones can often lead to acromegaly, hyperprolactinemia, Cushing’s disease, and hyperthyroidism.
Screening
Endocrine tests may identify reduced or increased hormone levels.
Lateral cranial x-ray: Occasionally, an enlarged pituitary fossa may be found, but the diagnosis is not conclusive.
Visual field examination: upper temporal quadrant blindness and bilateral temporal hemianopsia are common.
MRI is superior to CT. 10% of the normal population can be examined for microscopic lesions in the pituitary fossa (pituitary ependymoma), which appear consistent with pituitary microadenoma.
Differential diagnosis
The remaining common tumors in the saddle area are craniopharyngioma, lacunar cyst, and the relatively uncommon meningioma, germ cell tumor, and malformation tumor. [3]
Craniopharyngioma is a benign cystic tumor growing on the saddle. It presents with headache, visual field defects and pituitary hypoplasia (which manifests as growth disturbances because it often occurs in children and adolescents).
Other disorders that can cause headache, visual field defects, visual impairment and endocrine dysfunction.
Treatment
Treatment depends on the type of tumor and whether it invades the surrounding brain tissue. Hormone-secreting tumors can be treated with surgery, radiation therapy, or drugs such as bromocriptine (for prolactin adenomas) or growth inhibitors (for growth hormone-type adenomas).
Surgery
The vast majority (about 95%) of non-functioning pituitary tumors and adrenocorticotropic pituitary tumors are treated with transnasal butterfly surgery. A small number of patients require craniotomy. Large nonfunctioning pituitary tumors often grow beyond the pituitary borders and require treatment with radiation therapy. Urgent surgery is often required for rapid deterioration of vision.
Radiotherapy
It is indicated for
lesions that have not been completely resected and cannot be completely resected by reoperation
Patients who are still hypersecretory after surgery
Growth inhibitor analogues
These drugs, such as octreotide acetate and lanreotide, are the mainstay of treatment for growth hormone pituitary tumors, and are also used for the rare thyrotropin pituitary tumors. Octreotide and lanotide can control hormone secretion in most patients with acromegaly and can even shrink tumors.
Bromocriptine
The application of bromocriptine has been successful in treating patients with prolactinotropic pituitary tumors. The dopamine agonists cartegolide and quigolide (not yet introduced in mainland China) have been successfully used in patients who have relapsed or failed after bromocriptine treatment, with minimal side effects. Adrenal steroid hormone inhibitors, such as mitotane, ketoconazole, can also be applied while waiting for radiotherapy to work.
Recurrent pituitary tumors
Patients with recurrence after surgery may be reoperated or treated with radiation therapy.
Certain selected patients with recurrence may be treated with radiation again for long-term control of focal symptoms, such as improvement or maintenance of visual status.
Complications
Pituitary tumor stroke – sudden onset of hypopituitarism due to acute infarction or hemorrhage of a pituitary adenoma.
Prognosis
After treatment, 90% of patients with microadenomas and 50-60% of patients with macroadenomas are cured or in remission.