What is an Adenoma?
A benign epithelial tumor in which the cells form recognizable glandular structures or in which the cells are derived from glandular epithelium.
These tumors are usually found accidentally in the brain during certain investigations hence they are known as Incidentaloma, when found with other investigations such as MRI, CT-Scan & SPECT.
These patients are usually A-symptomatic & have no symptoms, even people do not know that they may be carrying this tumor for years in their cranial cavity.
Some times the patients may have some vague complains of Headache, vertigo, blurring of vision. Whereas, females may encounter this condition soon after their first visit to a Gynecologist may be with the complain of irregular menstrual cycle or with a complain of infertility.
These tumors are mainly divided into 2 categories:
1. Functional (Secreting)
2. Non-Functional (Non-Secreting)
Further the Functional tumors are divided according to their Secretions:
1. Prolactin cell Adenoma
2. Growth hormone cell Adenoma
3. ACTH cell Adenoma
4. Gonadotroph cell Adenoma
5. Mixed Adenoma.
The Non-Functional Adenomas are silent do not secretes any hormone, hence no hormone specific symptoms are produced.
What is Pituitary Gland?
The pituitary gland is a small, bean-shaped organ that sits at the base of the brain, behind the bridge of the nose. It sits in a small pocket of bone in the base of the skull called the sella turcica.
The internal carotid arteries & the nerves that control eye movement lie on the sides of the pituitary. Directly above the pituitary gland is the optic chiasm, which is responsible for vision. The gland is basically responsible for the hormonal secretions & its regulation.
What if I have this tumor?
The tumor is more or less benign(non-cancerous) in nature only few of them are malignant & rapidly growing. Hence the tumor does not produce symptoms for years soon from its initial growth.
The Adenoma is said to be slow growing 1mm/year.
How will I know that I have the tumor?
If a patient is suffering from the Non-Functional Tumor it will not produce specific hormonal symptoms. The symptoms are produced due to the pressure effects on the adjacent structures as the cranial cavity is a bonny structure & does not have the ability to expand.
If the tumor is large (Macro-Adenoma sizes more then 10mm), usually produces the symptoms such as:
- Bi-temporal hemianopsia (Decreased ability to see the peripheral objects when eyes are focused to the central point of focus) or decreased field of vision.
- Blurring of vision
- Mood swings
If a patient is suffering from the Functional tumor secretory type usually produce the hormone specific symptoms:
- PROLACTIN SECRETING PITUTARY ADENOMA (PROLACTINOMA): The pituitary tumor causes & overproduction of prolactin, causing loss of menstrual periods & breast milk production in women. In men, high Prolactin levels can lower testosterone levels, leading to diminished sexual interest.
- GROWTH HORMONE SECRETING PITUTARY ADENOMA: An excessive production of growth hormone (GH) causes acromegaly in adults or gigantism in children. Symptoms include enlarged hands & feet & other changes in the body.
- ACTH SECRETING PITUTARY ADENOMA: Excessive ACTH hormone production causes Cushing’s disease. Symptoms include unexpected weight gain, easy bruising of the skin & muscle weakness.
- TSH SECRETING PITUTARY ADENOMA (THYROTROPINOMA): Excessive TSH hormone production leads to hyperthyroidism.
Associated features which Pituitary Adenoma shows are as follows:
When the tumor compresses the normal pituitary gland, it can cause it to fail leading to pituitary insufficiency (hypopituitarism). The symptoms will depend upon which hormone is involved.
- Reduction of sex hormones, luteinizing hormone (LH) and follicle-stimulating hormone (FSH).
- In men, this can lead to a low testosterone level, causing decreased sexual drive and impotence.
- In some cases, there can be loss of body and facial hair.
- In women, this can lead to infertility.
- Reduction in TSH production can lead to hypothyroidism, which can cause appetite loss, weight gain, fatigue and decreased mental function.
- Reduction in ACTH production causes adrenal insufficiency, because Cortisol production is reduced. Symptoms include fatigue, low blood pressure, electrolyte abnormalities. If severe, death can occur.
- Reduction in growth hormone (GH) production is called growth hormone insufficiency.
- In children, this results is stunted growth and delayed puberty.
- In adults, the effects can be subtle but can include generalized tiredness, loss of muscle mass and tone.
- Reduction in Prolactin production is uncommon and occurs with severe pituitary insufficiency.
- Large pituitary tumors can slightly elevate blood Prolactin levels. Doctors think this occurs because of compression of the pituitary stalk, the connection between the pituitary gland and the brain. It is called the “stalk effect.”
- In menopausal women, this can lead to reduction or loss of menstrual periods and/or breast milk production (galactorrhea).
- Prolactin levels are only slightly elevated, as opposed to prolactinomas in which the Prolactin level is usually very high.
Keeping these features in mind if a person experiences above mentioned features should go for some lab investigation & imaging techniques like:
- Serum Prolactin levels.
- Serum Prolactin level >200 mcg/L in a patient with a macroadenoma greater than 10 mm in size is diagnostic of a prolactinomas. Levels below that range in a macroadenoma suggest hyperprolactinemia secondary to hypothalamic compression.
- Growth hormone abnormalities
- Growth hormone (GH) levels are elevated in acromegaly but can fluctuate significantly.
- Intravenous (IV) GH levels every 5 minutes for 24 hours may show consistent elevation of GH.
- Oral glucose tolerance test is the definitive test for the diagnosis of acromegaly; a positive result is the failure of GH to decrease to < 1 mcg/L after ingesting 50-100 g of glucose.
- Thyrotrophin releasing Hormone (TRH), 200 mcg, can be given to increase the test’s accuracy. A GH level > 5 mcg/L suggests acromegaly.
- Failure to decrease the GH concentration to < 2 mcg/L after a glucose load and after TRH stimulation is highly suggestive of acromegaly
- Cushing disease and Cushing syndrome
- 24 hour urine is collected for free cortisol. Usually 2 baseline values are obtained.
- If Cortisol levels are increased abnormally, corticotrophin releasing factor (CRF) in a dose of 100 mcg can be given to differentiate between Cushing disease & other causes of hypercortisolism (ie, Cushing syndrome). With pituitary adenomas, Cortisol secretion is increased over the baseline.
- Glycoprotein hormones – Thyroid stimulating hormone, follicle stimulating hormone, luteinizing hormone.
- Pituitary adenomas that are associated with thyroid-stimulating hormone (TSH) hypersecretion are uncommon. These patients have increased T3 and T4 levels, hyperthyroidism & goiter with inappropriately high levels of TSH.
- Increased follicle stimulating hormone (FSH) levels may be apparent in the histologic examination of a pituitary adenoma in patients without apparent preoperative endocrine abnormalities & in some patients with hypogonadism.
- Increased luteinizing hormone (LH) levels also may be seen in patients with hypogonadism. The secreted hormone is not intact LH & serum testosterone levels are not increased.
How can I get Rid from this medical condition?
1. MEDICAL THERAPY: Usually the Hormone secreting tumors are best treated on medical therapy such as prolactinomas.
2. SURGICAL INTERVENTION: Keeping in mind that the brain is one of the most delicate & major organ of human body so many approaches are being performed to prevent the open cranium (skull) surgery which may include:
- Trans-sphenoidal (Endoscopic nasal approach)
- Key hole surgery via eyebrow
- Trans-labial Approach.
One of the major advancement in the field on Radio-surgery is:
- Gamma knife
- Stereo-tactic radio surgery
One of the major question the patient asks is about the recovery after surgery and its outcomes
The recovery after surgery depends upon the size of Adenoma, its nature, skills & number of surgeries the neurosurgeon have performed.
Usually the recovery is fast & the patient can go home within few days again depends on the approach the surgeon chooses. Sometimes the normal pituitary tissues are also excised during surgery which leads to the decreased hormonal production leading to hypo-pituitarism which shall sometimes requires life long hormone replacement therapy in the form or oral medications.
Another question, which people wants to know is that how to choose my surgeon?
The answer to this question is based on few questions to be asked from the doctor:
- Do you specialize in pituitary surgery?
- How many pituitary surgeries do you perform every week/month/year?
It is said that 2 – 5 operations per month are the minimum for a neurosurgeon to perform to maintain a high degree of surgical competency.
patients with Prolactin secreting macro adenomas should always be treated through surgery?
No patient with a pituitary Adenoma should go to surgery without a pituitary hormone level baseline test being done & a decision made as to whether medical or surgical treatment would be most appropriate. Decisions would be based upon the individual circumstances. In general, however, there is an increasing trend to treat these tumors with drugs to shrink the tumor mass. In many instances this is used as primary treatment, with surgery used only if drug therapy fails to bring about the desired tumor shrinkage.