The pituitary gland, often referred to as the "master gland," plays a crucial role in the endocrine system by regulating numerous physiological processes through hormone secretion. Pathology of the pituitary gland can lead to a range of disorders, primarily categorized into two types: functional and non-functional tumors, as well as other conditions that affect its structure and function.
Functional Tumors
These tumors secrete hormones that can lead to excess hormone levels and related syndromes:
- Prolactinomas: The most common type of pituitary tumor, secreting excess prolactin, which can cause galactorrhea, amenorrhea, and infertility.
- Growth Hormone-Secreting Tumors (Acromegaly): Overproduction of growth hormone, leading to enlarged extremities, facial changes, and increased risk of cardiovascular diseases.
- Corticotropin-Secreting Tumors (Cushing's Disease): Excess adrenocorticotropic hormone (ACTH) causing adrenal overproduction of cortisol, resulting in Cushing's syndrome with symptoms like weight gain, hypertension, and skin changes.
- Thyrotropin-Secreting Tumors: Rare tumors that produce thyroid-stimulating hormone (TSH) leading to hyperthyroidism.
Non-Functional Tumors
These tumors do not secrete hormones but can cause symptoms through mass effects, such as headaches, visual disturbances, and pituitary insufficiency due to compression of surrounding structures. They can be adenomas, craniopharyngiomas, or pituitary carcinomas.
Pituitary Insufficiency (Hypopituitarism)
This condition may arise from tumors, trauma, radiation, or other diseases affecting the gland, leading to deficiencies in one or more pituitary hormones. Symptoms vary widely depending on which hormones are deficient.
Inflammatory and Infectious Conditions
- Pituitary Apoplexy: Sudden hemorrhage or infarction in the pituitary gland, often presenting with severe headache, visual loss, and hormonal crisis.
- Hypophysitis: Inflammation of the pituitary gland, which can be autoimmune in nature or associated with infections.
Other Pathologies
- Empty Sella Syndrome: Consequence of herniation of the subarachnoid space, leading to a flattened pituitary gland.
- Pituitary Adenocarcinoma: A rare malignancy of the pituitary gland that may exhibit aggressive behavior and metastasize.
Diagnosis and Treatment
Diagnosis often involves imaging (MRI), hormone level tests, and sometimes biopsy. Treatment depends on the underlying pathology and may include surgical resection, medication (e.g., dopamine agonists for prolactinomas), and hormone replacement therapy for deficiencies.
Understanding pituitary gland pathology is vital due to its significant impact on overall endocrine function and health.