Most patients with thyroid adenoma can be managed by watchful waiting (without surgical excision) with regular monitoring. However, some patients still choose surgery after being fully informed of the risks. Regular monitoring mainly consists of watching for changes in nodule size and symptoms, and repeat ultrasonography or needle aspiration biopsy if the nodule grows.

There are three main treatments for Hürthle cell adenomas. Once the adenoma is detected most often the nodules removed to prevent the cells from later metastisizing. A total thyroidectomy is often performed, this results in a complete removal of the thyroid. Some patients may only have half of their thyroid removed, this is known as a thyroid lobectomy. Another treatment option includes pharmacological suppression of thyroid hormone. The thyroid gland is responsible for producing the thyroid hormones triiodothyronine (T3) and thyroxine (T4). Patients with suppressed thyroid function often require oral thyroid replacement (e.g. levothyroxine) in order to maintain normal thyroid hormone levels. The final treatment option is RAI abaltion (radioactive iodine ablation). This treatment option is used to destroy infected thyroid cells after total thyroidectomy. This treatment does not change prognosis of disease, but will diminish the recurrence rate. Also, Hürthle cells do not respond well to RAI. However, often doctors suggest this treatment to patients with Hürthle cell adenoma and Hürthle cell carcinoma because some Hürthle cells will respond and it will kill remaining tissue.

Treatment options depend on the type of tumor and on its size:

- Prolactinomas are most often treated with cabergoline or quinagolide (both dopamine agonists), which decrease tumor size as well as alleviates symptoms, followed by serial imaging to detect any increase in size. Treatment where the tumor is large can be with radiation therapy or surgery, and patients generally respond well. Efforts have been made to use a progesterone antagonist for the treatment of prolactinomas, but so far have not proved successful.

- Somatotrophic adenomas respond to octreotide, a long-acting somatostatin analog, in many but not all cases according to a review of the medical literature. Unlike prolactinomas, thyrotrophic adenomas characteristically respond poorly to dopamine agonist treatment.

- Surgery is a common treatment for pituitary tumors. The normal approach is Trans-sphenoidal adenectomy, which usually can remove the tumor without affecting the brain or optic nerves.

- Danazol is a steroid compound that has been labelled as an "Anterior pituitary suppressant".

Some authors feel that all hepatocellular adenoma should be resected, because of the risk of rupture causing bleeding and because they may contain malignant cells. Current recommendations are that all hepatic adenomas should be resected, as long as they are surgically accessible and the patient is a reasonable operative candidate. Patients with adenomas should avoid oral contraceptives or hormonal replacement therapy.

Pregnancy could cause the adenoma to grow faster, so patients with hepatic adenomas should avoid pregnancy.

Treatment may include the following:

- Surgery with or without radiation

- Radiotherapy

Fast neutron therapy has been used successfully to treat salivary gland tumors, and has shown to be significantly more effective than photons in studies treating unresectable salivary gland tumors.

- Chemotherapy

Treatment of a thyroid nodule depends on many things including size of the nodule, age of the patient, the type of thyroid cancer, and whether or not it has spread to other tissues in the body.

If the nodule is benign, patients may receive thyroxine therapy to suppress thyroid-stimulating hormone and should be reevaluated in 6 months. However, if the benign nodule is inhibiting the patient's normal functions of life; such as breathing, speaking, or swallowing, the thyroid may need to be removed.

Sometimes only part of the thyroid is removed in an attempt to avoid causing hypothyroidism. There's still a risk of hypothyroidism though, as the remaining thyroid tissue may not be able to produce enough hormones in the long-run.

If the nodule is malignant or has indeterminate cytologic features, it may require surgery. A thyroidectomy is a medium risk surgery that can result complications if not performed correctly. Problems with the voice, nerve or muscular damage, or bleeding from a lacerated blood vessel are rare but serious complications that may occur. After removing the thyroid, the patient must be supplied with a replacement hormone for the rest of their life. This is commonly a daily oral medication prescribed by their endocrinologist.

Radioactive iodine-131 is used in patients with papillary or follicular thyroid cancer for ablation of residual thyroid tissue after surgery and for the treatment of thyroid cancer. Patients with medullary, anaplastic, and most Hurthle cell cancers do not benefit from this therapy. External irradiation may be used when the cancer is unresectable, when it recurs after resection, or to relieve pain from bone metastasis.

Levothyroxine is a stereoisomer of thyroxine which is degraded much slower and can be administered once daily in patients with hypothyroidism.

Almost all thyroid adenomas are follicular adenomas. Follicular adenomas can be described as "cold", "warm" or "hot" depending on their level of function. Histopathologically, follicular adenomas can be classified according to their cellular architecture and relative amounts of cellularity and colloid into the following types:

- Fetal (microfollicular) - these have the potential for microinvasion. These consist of small, closely packed follicles lined with epithelium.

- colloid (macrofollicular) - these do "not" have any potential for microinvasion

- embryonal (atypical) - have the potential for microinvasion.

- Hürthle cell adenoma (oxyphil or oncocytic tumor) - have the potential for microinvasion.

- Hyalinizing trabecular adenoma

Papillary adenomas are very rare.

An endocrine gland neoplasm is a neoplasm affecting one or more glands of the endocrine system.

Examples include:

- Adrenal tumor

- Pituitary adenoma

The most common form is thyroid cancer.

Condition such as pancreatic cancer or ovarian cancer can be considered endocrine tumors, or classified under other systems.

Pinealoma is often grouped with brain tumors because of its location.

A physician's response to detecting an adenoma in a patient will vary according to the type and location of the adenoma among other factors. Different adenomas will grow at different rates, but typically physicians can anticipate the rates of growth because some types of common adenomas progress similarly in most patients. Two common responses are removing the adenoma with surgery and then monitoring the patient according to established guidelines.

One common example of treatment is the response recommended by specialty professional organizations upon removing adenomatous polyps from a patient. In the common case of removing one or two of these polyps from the colon from a patient with no particular risk factors for cancer, thereafter the best practice is to resume surveillance colonoscopy after 5–10 years rather than repeating it more frequently than the standard recommendation.

An alternative using high intensity focused ultrasound or HIFU has recently proved its effectiveness in treating benign thyroid nodules. This method is noninvasive, without general anesthesia and is performed in an ambulatory setting. Ultrasound waves are focused and produce heat enabling to destroy thyroid nodules.

Focused ultrasounds have been used to treat other benign tumors, such as breast fibroadenomas and fibroid disease in the uterus.

Surgery is the only cure for parathyroid adenomas. It is successful about 95% of the time. Parathyroidectomy is the removal of the affected gland(s). The standard of treatment of primary hyperparathyroidism was formerly a surgical technique called bilateral neck exploration, in which the neck was opened on both sides, the parathyroids were identified, and the affected tissue was removed. By the 1980s, unilateral exploration became more common. Parathyroidectomy can now be performed in a minimally invasive fashion, mainly because imaging techniques can pinpoint the location of the tissue. Minimally invasive techniques include smaller open procedures, radio-guided and video-assisted procedures, and totally endoscopic surgery.

Before surgery is attempted, the affected glandular tissue must be located. Though the parathyroid glands are usually located on the back of the thyroid, their position is variable. Some people have one or more parathyroid glands elsewhere in the neck anatomy or in the chest. About 10% of parathyroid adenomas are ectopic, located not along the back of the thyroid but elsewhere in the body, sometimes in the mediastinum of the chest. This can make them difficult to locate, so various imaging techniques are used, such as the sestamibi scan, single-photon emission computed tomography (SPECT), ultrasound, MRI, and CT scans. sometimes parathyroid adenomas can be ablated by ethanol injection, guided by ultrasound.

Parathyroid carcinoma is sometimes diagnosed during surgery for primary hyperparathyroidism. If the surgeon suspects carcinoma based on severity or invasion of surrounding tissues by a firm parathyroid tumor, aggressive excision is performed, including the thyroid and surrounding tissues as necessary.

Agents such as calcimimetics (for example, cinacalcet) are used to mimic calcium and are able to activate the parathyroid calcium-sensing receptor (making the parathyroid gland "think" we have more calcium than we actually do), therefore lowering the calcium level, in an attempt to decrease the hypercalcemia.

A parathyroid neoplasm is a tumor of the parathyroid gland.

Types include:

- Parathyroid adenoma

- Parathyroid carcinoma

An adenoma (from Greek αδένας, "", "gland" + -ώμα, "", "tumor") (; plural adenomas or adenomata ) is a benign tumor of epithelial tissue with glandular origin, glandular characteristics, or both. Adenomas can grow from many glandular organs, including the adrenal glands, pituitary gland, thyroid, prostate, and others. Some adenomas grow from epithelial tissue in nonglandular areas but express glandular tissue structure (as can happen in familial polyposis coli). Although adenomas are benign, over time they may transform to become malignant, at which point they are called adenocarcinomas. Most adenomas do not transform. But even while benign, they have the potential to cause serious health complications by compressing other structures (mass effect) and by producing large amounts of hormones in an unregulated, non-feedback-dependent manner (causing paraneoplastic syndromes). Some adenomas are too small to be seen macroscopically but can still cause clinical symptoms.

An oncocytoma is a tumor made up of oncocytes, epithelial cells characterized by an excessive amount of mitochondria, resulting in an abundant acidophilic, granular cytoplasm. The cells and the tumor that they compose are often benign but sometimes may be premalignant or malignant.

Hürthle cell adenoma is a rare benign tumor, typically seen in women between the ages of 70 and 80 years old. This adenoma is characterized by a mass of benign Hürthle cells (Askanazy cells). Typically such a mass is removed because it is not easy to predict whether it will transform into the malignant counterpart, a subtype of follicular thyroid cancer called a Hürthle cell carcinoma.

A parathyroid adenoma is a benign tumor of the parathyroid gland. It generally causes hyperparathyroidism; there are very few reports of parathyroid adenomas that were not associated with hyperparathyroidism.

A human being usually has four parathyroid glands located on the back surface of the thyroid in the neck. The parathyroids secrete parathyroid hormone (PTH), which increases the concentration of calcium in the blood by inducing the bones to release calcium into the blood and the kidneys to reabsorb it from the urine into the blood. When a parathyroid adenoma causes hyperparathyroidism, more parathyroid hormone is secreted, causing the calcium concentration of the blood to rise, resulting in hypercalcemia.

Thyroid neoplasm is a neoplasm or tumor of the thyroid. It can be a benign tumor such as thyroid adenoma, or it can be a malignant neoplasm (thyroid cancer), such as papillary, follicular, medullary or anaplastic thyroid cancer. Most patients are 25 to 65 years of age when first diagnosed; women are more affected than men. The estimated number of new cases of thyroid cancer in the United States in 2010 is 44,670 compared to only 1,690 deaths. Of all thyroid nodules discovered, only about 5 percent are cancerous, and under 3 percent of those result in fatalities.

Carcinomas that metastasize into the pituitary gland are uncommon and typically seen in the elderly, with lung and breast cancers being the most prevalent, In breast cancer patients, metastases to the pituitary gland occur in approximately 6-8% of cases.

Symptomatic pituitary metastases account for only 7% of reported cases. In those who are symptomatic Diabetes insipidus often occurs with rates approximately 29-71%. Other commonly reported symptoms include anterior pituitary dysfunction, visual field defects, headache/pain, and ophthalmoplegia.

A non-minimally invasive Hürthle cell carcinoma is typically treated by a total thyroidectomy followed by radioactive iodine therapy. A Hürthle cell adenoma or a minimally invasive tumor can be treated by a thyroid lobectomy, although some surgeons will perform a total thyroidectomy to prevent the tumor from reappearing and metastasizing.

A modified radical neck dissection may be performed for clinically positive lymph nodes.

A adrenocortical adenoma (or adrenal cortical adenoma, or sometimes simply adrenal adenoma) is a benign tumor of the adrenal cortex.

It can present with Cushing's syndrome or primary aldosteronism. They may also secrete androgens, causing hyperandrogenism. Also, they are often diagnosed incidentally as incidentalomas.

Is a well circumscribed, yellow tumour in the adrenal cortex, which is usually 2–5 cm in diameter. The color of the tumour, as with adrenal cortex as a whole, is due to the stored lipid (mainly cholesterol), from which the cortical hormones are synthesized. These tumors are frequent incidental findings at post mortem examination, and appear to have produced no significant metabolic disorder; only a very small percentage lead to Cushing's syndrome. Nevertheless, these apparently non-functioning adenomas are most often encountered in elder obese people. There is some debate that they may really represent nodules in diffuse nodular cortical hyperplasia.

Very occasionally, a true adrenal cortical adenoma is associated with the clinical manifestations of Conn's syndrome, and can be shown to be excreting mineralocorticoids.

Toxic multinodular goiter can be treated with antithyroid medications such as propylthiouracil or methimazole, radioactive iodine, or with surgery.

Another treatment option is injection of ethanol into the nodules.

Some studies have shown that thyroglobulin (Tg) testing combined with neck ultrasound is more productive in finding disease recurrence than full- or whole-body scans (WBS) using radioactive iodine. However, current protocol (in the USA) suggests a small number of clean annual WBS are required before relying on Tg testing plus neck ultrasound. When needed, whole body scans consist of withdrawal from thyroxine medication and/or injection of recombinant human Thyroid stimulating hormone (TSH). In both cases, a low iodine diet regimen must also be followed to optimize the takeup of the radioactive iodine dose. Low dose radioiodine of a few millicuries is administered. Full body nuclear medicine scan follows using a gamma camera. Scan doses of radioactive iodine may be I or I.

Recombinant human TSH, commercial name Thyrogen, is produced in cell culture from genetically engineered hamster cells.

Even though there is no evidence of malignant potential, transurethral resection is recommended together with long-term antibiotic prophylaxis for at least one year after resection. Prolonged antibiotic therapy is suggested due to the frequent finding of UTI as an associated or causative factor.