The pituitary gland, often referred to as the “master gland,” is a small but powerful organ located at the base of the brain. Despite its small size, this pea-sized gland plays a crucial role in regulating various bodily functions by producing and releasing hormones. These hormones control processes such as growth, metabolism, reproduction, and stress response. However, when a tumour develops in the pituitary gland, it can disrupt this delicate hormonal balance, leading to various health issues.
Pituitary tumours are abnormal growths within the pituitary gland. The vast majority of these tumours are benign adenomas, meaning they are non-cancerous and do not spread to other parts of the body. Despite the presence of benign, pituitary tumours can cause significant problems due to their location and their impact on hormone production.
The two main categories of pituitary tumors are:
Functioning (Secretory) tumours: These tumours produce excess hormones, leading to an overproduction of specific hormones in the body.
Non-functioning (Non-Secretory) tumours: These tumours do not produce excess hormones but can cause symptoms by pressing on surrounding tissues, including the pituitary gland itself and the optic nerves.
Pituitary tumours can disrupt hormone production in various ways, and the specific effects depend on the type of tumour and the hormones affected.
Excess hormone production:
• Prolactinomas: These tumours produce excess prolactin, which can lead to unexpected milk production and the absence of menstrual periods in women, and reduced testosterone in men.
• Somatotroph Adenomas: These tumors secrete excess growth hormone, leading to abnormal growth of hands, feet, and facial features in adults and excessive growth and height in children.
• Corticotroph Adenomas: These tumors overproduce adrenocorticotropic hormone (ACTH), resulting in Cushing’s disease, marked by weight gain, high blood pressure, diabetes, and osteoporosis.
• Thyrotroph Adenomas: These rare tumors produce thyroid-stimulating hormone (TSH), causing hyperthyroidism, leading to symptoms like weight loss, rapid heartbeat, and anxiety.
Reduced Hormone Production:
• Non-functioning tumors or large functioning tumours can compress the normal pituitary tissue, leading to decreased hormone production (hypopituitarism).
• Adrenal insufficiency: Reduced ACTH can lead to decreased cortisol production, causing fatigue, weakness and low blood pressure.
• Hypothyroidism: Insufficient TSH production can result in low thyroid hormone levels, leading to weight gain, fatigue, and depression.
• Growth hormone deficiency: Lack of growth hormone can cause stunted growth in children and a range of symptoms in adults, including decreased muscle mass and energy levels.
• Gonadal dysfunction: Reduced production of gonadotropins (LH and FSH) can lead to irregular menstrual cycles in women and low testosterone levels in men, affecting fertility and sexual function.
• Diabetes insipidus: If the tumor affects the posterior pituitary gland, it can disrupt antidiuretic hormone (ADH) production, leading to excessive thirst and urination.
The symptoms of a pituitary tumour can vary widely depending on the type and size of the tumor and the hormones affected. Common symptoms include headaches, vision problems, unexplained weight changes, menstrual irregularities, sexual dysfunction, fatigue, and mood changes.
Diagnosing a pituitary tumour typically involves a combination of a medical history review, physical examination, blood tests to measure hormone levels, and imaging studies such as magnetic resonance imaging (MRI) or computed tomography (CT) scans to visualise the tumour.
Treatment for pituitary tumours depends on the type, size, and effects of the tumour. Medications are often used for certain hormone-producing tumors to help control hormone levels. For instance, dopamine agonists can reduce prolactin levels in prolactinomas. Surgery may be necessary for the removal of the tumour, especially if it is pressing on surrounding structures or causing significant symptoms. Radiation therapy is another option that can be used to shrink the tumor or control its growth, particularly if surgery is not feasible or if the tumorrecurs. Moreover, hormone replacement therapy can help manage symptoms if the tumor or its treatment results in hormone deficiencies.
Recent pharmaceutical developments have shown promise in improving the management of pituitary tumours. Newer medications are being developed and tested to target specific pathways involved in tumour growth and hormone production. Furthermore, research into targeted therapies, such as inhibitors of the mTOR pathway and other molecular targets, is ongoing, offering hope for more precise and effective treatments in the future. These advancements in pharmacology are paving the way for better management of pituitary tumours, aiming to improve patient outcomes and quality of life.
(The author, Dr. Aravind Badiger, is a Technical Director of BDR Pharmaceuticals.)
