Adenoma: Definition, Types, Causes, Symptoms, Diagnosis and Treatment

It is a tumor, generally benign, that occurs in the glandular tissue of various organs.

The word adenoma is derived from “adeno” which means “belonging to a gland “.

As benign growths they can grow in size to press on the surrounding vital structures and lead to serious consequences.

Large adenomas in vital hormone-producing organs increase the hormones produced by the organ and lead to serious complications called paraneoplastic syndromes .

Adenomas de colon

The colon is the most common organ that is affected by adenomas.

Colon tubular adenoma is a tumor-producing condition that grows in the colon.

Tubular adenomas are considered “premalignant” tumors.

This means that these tumors can become malignant over time.

Most of these tumors are first noticed during a screening colonoscopy; a procedure that allows you to see images of the inner lining of the colon.

In most cases, these tumors are less than 1 cm in size.

If colon tubular adenomas are found early enough, they can be removed and the risk of developing cancer is low.

However, if they have time to proliferate and grow, the risk of cancer is quite high.

Causes of tubular adenoma of the colon

Colon tubular adenoma is caused by genetic mutations that cause dysplasia.

Dysplasia is the phenomenon of disorderly growth of the epithelial lining of the colon.

Genetic mutations lead to cell growth rates at abnormally high rates.

This causes the cells to grow abnormally, forming the characteristic tumors of a tubular adenoma.

Genetic mutations can be inherited or caused by exposure to various environmental factors.

  • Inherited genetic mutations include those that result from familial adenomatous polyposis.
  • Environmental factors that cause genetic mutations can include radiation, harmful chemicals in the air, among others.

Signs and symptoms of colon tubular adenoma

In rare cases, the signs and symptoms of colon tubular adenoma may include:

  • Tumor in the colon that causes blockages (if the tumors are large).
  • Bleeding from the anus, mucus mixed with stool; both in rare cases.
  • In rare cases, diarrhea or constipation .

Most people with tubular adenoma of the colon show no signs or symptoms.

People usually don’t realize they have a tubular adenoma until the doctor sees it during a screening colonoscopy.

Diagnosis of tubular adenoma of the colon

A diagnosis of tubular adenoma of the colon may include:
Physical exam with evaluation of medical history.

Tubular adenomas are usually first diagnosed during a colonoscopy exam:

  • During this procedure, a thin, flexible tube (called a colonoscope) with a video camera attached to the body is inserted to view the colon and rectum.
  • If there is a tubular adenoma, a projection will appear on the screen originating from the epithelial lining of the colon.
  • During the colonoscopy , the tumor is removed and sent to a pathologist for examination.
  • The diagnosis of tubular adenoma of the colon can be made by studying the tumor under a microscope.

Many clinical conditions can have similar signs and symptoms.

Your should perform additional tests to rule out other clinical conditions to reach a definitive diagnosis.

Complications of tubular adenoma of the colon

Complications can arise if tubular adenomas of the colon are not treated.

  • If the tumor grows too large, it can become cancerous and become colon or rectal cancer.
  • This is a life-threatening condition, if not properly diagnosed and treated. However, this process from tubular adenoma to cancer can take many years.

Treatment of a tubular adenoma of the colon

Tubular adenomas are treated immediately, once discovered, through screening colonoscopy.

The gastroenterologist will remove the tumor by polypectomy or will remove the tumor by cauterization.

If the residual tumor remains in the colon after removal, you may need to undergo another colonoscopy, in order to remove it completely.

If the tumor has grown too large to be removed by polypectomy, surgery may be required to remove part of the colon.

This is called a segmental colectomy. This involves making an incision in the abdomen so that the colon can be reached.

Pituitary gland adenomas

These are considered incidental findings in many individuals and generally respond well to surgical removal of the tumor.

And the most common of adenomas is called a prolactinoma. These are more commonly seen among women.

Hormonal therapies and Bromocriptine therapy are recommended.

Pituitary adenomas are a type of tumor that originates in the anterior pituitary gland.

The pituitary gland is a gland located at the base of the brain with two parts: the anterior pituitary gland or adenohypophysis and the neurohypophysis.

Causes of pituitary gland adenomas

Pituitary adenomas are benign tumors that arise from one of the five types of cells present in the anterior pituitary gland.

Depending on the cells affected, the tumor produces a hormone or another particular type:

Growth hormone producing cells, prolactin producing cells, thyroid stimulating hormone producing cells.

The stimulation of hormone-producing cells cells that produce adrenal glands that stimulate the hormones of the ovarian cycle.

But some tumors produce more than one hormone, most of the time it is the production of growth hormone and prolactin together.

And other tumors that do not produce any hormones or cause the loss of the manufacture of some of the hormones of the pituitary.

Symptoms of pituitary gland adenomas

The clinical manifestations of pituitary adenoma will depend on two things:

Hormone-secreting tumors, the type of hormone or hormones they produce; and if hormones don’t, symptoms that result from growth or blockage in the production of other hormones.

In the case of prolactinoma (prolactin-producing tumor), there may be milk secretion outside of pregnancy.

In the case of growth hormone hypersecretion there will be an accumulation of people (gigantism or acromegaly).

The tumor produces an excessive production of the hormone that stimulates the adrenal glands producing Cushing’s syndrome, the tumor and that produces an increased amount of thyroid stimulating hormone that causes hyperthyroidism.

The clinical evidence of tumor growth will be the result of compression of the adjacent structures.

Therefore, when the adenoma grows higher and higher, it affects the optic chiasm, that is, the combination of optic nerves that transmit nerve impulses to the retina.

This can be characteristic symptoms such as loss of vision in the most lateral areas of the visual field.

At the same time, if the growth of the adenoma is mainly mediated, secondary regions can affect the III, IV and V cranial nerves.

Hence symptoms like drooping eyelid, paralysis of eye movements, and pain may appear in a tingling face.

But if the growth of the adenoma affects the hypothalamus, symptoms can manifest excessive food intake, control of body temperature problems and diabetes insipidus.

The tumor growth that produces hormones can affect the lack of growth of one or more hormones, giving a partial or total lack of pituitary function, which is called hypopituitarism.

Diagnosis of pituitary gland adenomas

Diagnosis begins with medical suspicion and blood tests for hormones.

The study is complemented with imaging tests to locate and determine the extent of the adenoma and the possible involvement of adjacent structures.

The best technique is magnetic resonance imaging.

Treatment of pituitary gland adenomas

Treatment may consist of removing or blocking the tumor and treating excess hormones.

This can be achieved through three therapeutic modalities: medical treatment, surgery, and radiation therapy.

Surgical treatment is generally performed through the nose (transsphenoidal surgery), and it is a very safe technique.

For small adenomas they have a high cure rate, while for larger tumors it is lower.

The results after surgery are usually very fast, but they can reappear in the following years.

The main drawback is that when the pituitary gland is removed, a deficiency of one or more pituitary hormones can occur, leading to hypopituitarism.

Radiation therapy is usually effective in slowing the growth of an adenoma, although its results often take time and generally do not bring symptoms under control quickly.

It can be used as an adjunct after surgery.

Medical treatment is usually carried out as a hypersecretion of the predominant hormone.

For prolactinomas, the choice is cabergoline or bromocriptine; excessive secretion of growth hormone and thyroid stimulating hormone of choice is octreotide.

Thyroid gland adenomas

The parathyroid glands are located in the neck, in the thyroid gland. Its function is to regulate how the body uses calcium.

Sometimes benign (non-cancerous) growths called adenomas appear on one or more of an individual’s parathyroid glands.

Adenomas cause the parathyroid gland to make more parathyroid hormone than the body needs, a condition called primary hypoparathyroidism.

Too much parathyroid hormone disrupts the body’s normal calcium balance, increasing the amount of calcium in the bloodstream.

A similar but less common condition, called secondary hyperparathyroidism, can occur in people with chronic kidney failure.

Too much calcium in the blood (hypercalcemia) may not cause any symptoms at all, or it may cause a number of symptoms and medical conditions.

These include:

  • Depression or mental confusion.
  • Kidney stones
  • Bone and joint pain
  • Abdominal pain.
  • General aches and pains with no obvious cause.

Parathyroid adenomas are usually discovered when an above-normal calcium level appears on a routine blood test, particularly in people without symptoms.

Doctors then confirm the diagnosis of primary hyperparathyroidism with a test that shows that parathyroid hormone levels in the blood are higher than normal.

Parathyroid adenomas are usually discovered when a higher-than-normal calcium level appears on a routine blood test.

The most common treatment is to remove the enlarged gland (or glands). This surgery cures the problem 95% of the time.

Instead of surgery, some people with mild or no symptoms of primary hyperparathyroidism may decide to try hormone replacement therapy or drug options.

Breast adenomas

These commonly affect young women and need a biopsy to rule out cancer.

Surgical removal is the best possible therapy.

Fibroadenomas of the breast usually appear in young women, even teenagers.

In adult women, mammary adenomas generally decrease in size over time, however in adolescents they tend to grow.

The causes of breast adenomas are still unknown.

Painless, easy-to-move lumps with clearly defined borders that can be felt when performing breast self-examination are seen in breast adenoma.

These characteristics indicate to a doctor that the lumps are less likely to be cancerous.

Breast adenomas are removed if growth is observed or causes any symptoms.

If multiple lumps have been removed and found to be non-cancerous, the doctor may decide not to remove new lumps that develop to prevent them from recurring repeatedly.

Women should undergo regular check-ups to be able to verify the changes.

To make sure breast adenomas are not cancerous, part or all of the adenoma is usually removed and examined with a tissue biopsy.

Adrenal gland adenomas

Adrenal gland adenomas are very common and rarely cancerous.

Adrenal gland adenomas generally do not cause any signs or symptoms and rarely require treatment.

They are generally small, and on occasion some can become “active” meaning that they produce hormones, often in excess of what the adrenal glands typically produce.

Elevated levels of these hormones can lead to complications, such as primary aldosteronism, Cushing’s syndrome, and other medical conditions.

Excess cortisol causes Cushing’s syndrome and when they secrete excess aldosterone, Conn’s syndrome can be caused.

When adenomas promote excess production of androgens, and male sex hormones can cause hyperandrogenism.

Functional adrenal adenomas can be treated with surgery and medications.

They are often found incidentally during imaging studies of the abdomen, in which case they are known as adrenal incidentalomas.

Kidney adenoma

Adenomas of the kidneys originate in the renal tubules of the cortex and appear as discrete, dull yellow masses.

Histologically, they are very similar to a well-differentiated renal cell carcinoma.

Small solid kidney tumors (less than 3 cm) were previously thought to be benign because they rarely metastasized; its histological similarity to renal cell carcinoma now results in a treatment similar to its malignant relationship, that is, surgical removal.

The two adrenal glands, one in each kidney, produce hormones.

Most adrenal gland adenomas don’t cause any problems, they just take up space.

But some of them are functional tumors, that means they produce the same hormones as the adrenal glands.

The extra hormones from the tumor can lead to various conditions, such as Cushing’s syndrome.

Usually surgery and medicine can successfully treat symptoms.

Other adenomas

There are rare adenomas that include those that affect organs such as the appendix, lungs and liver.