Hepatic adenomas are related to glycogen storage diseases, type 1, as well as anabolic steroid use.

Patients with thyroid oncocytomas present with a thyroid nodule, usually with normal thyroid function. If the tumor is big or invasive, there may be other symptoms such as difficulty swallowing or talking.

The diagnosis of salivary gland tumors utilize both tissue sampling and radiographic studies. Tissue sampling procedures include fine needle aspiration (FNA) and core needle biopsy (bigger needle comparing to FNA). Both of these procedures can be done in an outpatient setting. Diagnostic imaging techniques for salivary gland tumors include ultrasound, computer tomography (CT) and magnetic resonance imaging (MRI).

Fine needle aspiration biopsy (FNA), operated in experienced hands, can determine whether the tumor is malignant in nature with sensitivity around 90%. FNA can also distinguish primary salivary tumor from metastatic disease.

Core needle biopsy can also be done in outpatient setting. It is more invasive but is more accurate compared to FNA with diagnostic accuracy greater than 97%. Furthermore, core needle biopsy allows more accurate histological typing of the tumor.

In terms of imaging studies, ultrasound can determine and characterize superficial parotid tumors. Certain types of salivary gland tumors have certain sonographic characteristics on ultrasound. Ultrasound is also frequently used to guide FNA or core needle biopsy.

CT allows direct, bilateral visualization of the salivary gland tumor and provides information about overall dimension and tissue invasion. CT is excellent for demonstrating bony invasion. MRI provides superior soft tissue delineation such as perineural invasion when compared to CT only.

Pituitary incidentalomas are pituitary tumors that are characterized as an incidental finding. They are often discovered by computed tomography (CT) or magnetic resonance imaging (MRI), performed in the evaluation of unrelated medical conditions such as suspected head trauma, in cancer staging or in the evaluation of nonspecific symptoms such as dizziness and headache. It is not uncommon for them to be discovered at autopsy. In a meta-analysis, adenomas were found in an average of 16.7% in postmortem studies, with most being microadenomas (<10mm); macrodenomas accounted for only 0.16% to 0.2% of the decedents. While non-secreting, noninvasive pituitary microadenomas are generally considered to be literally as well as clinically benign, there are to date scant studies of low quality to support this assertion.

It has been recommended in the current Clinical Practice Guidelines (2011) by the Endocrine Society - a professional, international medical organization in the field of endocrinology and metabolism - that all patients with pituitary incidentalomas undergo a complete medical history and physical examination, laboratory evaluations to screen for hormone hypersecretion and for hypopituitarism. If the lesion is in close proximity to the optic nerves or optic chiasm, a visual field examination should be performed. For those with incidentalomas which do not require surgical removal, follow up clinical assessments and neuroimaging should be performed as well follow-up visual field examinations for incidentalomas that abut or compress the optic nerve and chiasm and follow-up endocrine testing for macroincidentalomas.

Thyroid oncocytomas can be benign (adenomas) or malignant (carcinomas). Grossly, oncocytic adenomas are encapsulated, solid nodules with a characteristic brown cut surface. The gross appearance of a minimally invasive oncocytic carcinoma is indistinguishable to that of an adenoma, while widely invasive oncocytic carcinomas are obviously invasive macroscopically and display pervasive vascular invasion with multifocal involvement of the thyroid gland. There are no reliable cytologic features which distinguish oncocytic adenomas from carcinomas and the only criterion for a diagnosis of malignancy is the identification of transcapsular or vascular invasion.

Hepatic adenomas are, typically, well-circumscribed nodules that consist of sheets of hepatocytes with a bubbly vacuolated cytoplasm. The hepatocytes are on a regular reticulin scaffold and less or equal to three cell thick.

The histologic diagnosis of hepatic adenomas can be aided by reticulin staining. In hepatic adenomas, the reticulin scaffold is preserved and hepatocytes do not form layers of four or more hepatocytes, as is seen in hepatocellular carcinoma.

Cells resemble normal hepatocytes and are traversed by blood vessels but lack portal tracts or central veins.

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.

JCT often is described as benign, however one case of metastasis has been reported, so its malignant potential is uncertain. In most cases the tumor is encapsulated.

Clinically, hypertension, especially when severe or poorly controlled, combined with evidence of a kidney tumor via imaging or gross examination suggest a JCT. However, other kidney tumors can cause hypertension by secreting renin. JCTs have a variable appearance and have often being misdiagnosed as renal cell carcinomas; dynamic computed tomography is helpful in the differential diagnosis.

Post-operatively, the presence of renin granules in pathology specimens as well as immunohistochemical analyses could help differentiating this tumor from other primary renal tumors such as hemangiopericytoma, glomus tumor, metanephric adenoma, epithelioid angiomyolipoma, Wilms tumor, solitary fibrous tumor, and some epithelial neoplasms.

Unlike tumors of the posterior Pituitary, Pituitary adenomas are classified as endocrine tumors (not brain tumors). Pituitary adenomas are classified based upon anatomical, histological and functional criteria.

- Anatomically pituitary tumors are classified by their size based on radiological findings; either microadenomas (less than <10 mm) or macroadenomas (equal or greater than ≥10 mm).

- Histological classification utilizes an immunohistological characterization of the tumors in terms of their hormone production. Historically they were classed as either basophilic, acidophilic, or chromophobic on the basis of whether or not they took up the tinctorial stains hematoxylin and eosin. This classification has fallen into disuse, in favor of a classification based on what type of hormone is secreted by the tumor. Approximately 20-25% of adenomas do not secrete any readily identifiable active hormones ('non-functioning tumors') yet they are still sometimes referred to as 'chromophobic'.

- Functional classification is based upon the tumors endocrine activity as determined by serum hormone levels and pituitary tissue cellular hormone secretion detected via immunohistochemical staining. The "Percentage of hormone production cases" values are the fractions of adenomas producing each related hormone of each tumor type as compared to all cases of pituitary tumors, and does not directly correlate to the percentages of each tumor type because of smaller or greater incidences of absence of secretion of the expected hormone. Thus, nonsecretive adenomas may be either "null cell adenomas" or a more specific adenoma that, however, remains nonsecretive.

As metanephric adenomas are considered benign, they can be left in place, i.e. no treatment is needed.

They generally have a good prognosis. In one larger study, the 5-year and 10-year survival were over 90% and 80% respectively.

There are many diagnostic methods that can be used to determine the type of salivary gland tumour and if it is benign or malignant. Examples of diagnostic methods include:

Physical exam and history: An exam of the body to check general signs of health. The head, neck, mouth, and throat will be checked for signs of disease, such as lumps or anything else that seems unusual. A history of the patient's health habits and past illnesses and treatments will also be taken.

Endoscopy: A procedure to look at organs and tissues inside the body to check for abnormal areas. For salivary gland cancer, an endoscope is inserted into the mouth to look at the mouth, throat, and larynx. An endoscope is a thin, tube-like instrument with a light and a lens for viewing.

MRI

Biopsy: The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer.

Fine needle aspiration (FNA) biopsy: The removal of tissue or fluid using a thin needle. An FNA is the most common type of biopsy used for salivary gland cancer, and has been shown to produce accurate results when differentiating between benign and malignant tumours.

Radiographs: An OPG (orthopantomogram) can be taken to rule out mandibular involvement. A chest radiograph may also be taken to rule out any secondary tumours.

Ultrasound: Ultrasound can be used to initially assess a tumour that is located superficially in either the submandibular or parotid gland. It can distinguish an intrinsic from an extrinsic neoplasm. Ultrasonic images of malignant tumours include ill defined margins.

Patients treated with complete surgical excision can expect an excellent long term outcome without any problems. Recurrences may be seen in tumors which are incompletely excised.

Hyperparathyroidism is confirmed by blood tests such as calcium and PTH levels. A specific test for parathyroid adenoma is sestamibi parathyroid scintigraphy, the sestamibi scan. This nuclear imaging technique reveals the presence and location of pathological parathyroid tissue.

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.

While there is a wide age range at clinical presentation (12–85 years), most patients come to clinical attention at 55 years (mean). There is no gender difference.

Most of these tumors are treated with surgical removal. It is non recurrent.

From a pathology perspective, several tumors need to be considered in the differential diagnosis, including paraganglioma, ceruminous adenoma, metastatic adenocarcinoma, and meningioma.

Hürthle cell adenoma is the benign analogue of Hürthle cell carcinoma. This adenoma is extremely rare; when it occurs, it usually occurs in women. Often the adenoma is harmless but is removed after detection because its future course cannot be trusted. This mass can be detected and removed before transformation and metastasis. The tumor is often detected by imaging such as ultrasound. The location and size of the tumor may cause pressure and pain to the patient. But often the tumor goes undetected. After detection, the mass is tested using an invasive fine-needle aspiration biopsy.

Overall, the mainstay of the treatment for salivary gland tumor is surgical resection. Needle biopsy is highly recommended prior to surgery to confirm the diagnosis. More detailed surgical technique and the support for additional adjuvant radiotherapy depends on whether the tumor is malignant or benign.

Surgical treatment of parotid gland tumors is sometimes difficult, partly because of the anatomical relationship of the facial nerve and the parotid lodge, but also through the increased potential for postoperative relapse. Thus, detection of early stages of a tumor of the parotid gland is extremely important in terms of prognosis after surgery.

Generally, benign tumors of the parotid gland are treated with superficial(Patey's operation) or total parotidectomy with the latter being the more commonly practiced due to high incidence of recurrence. The facial nerve should be preserved whenever possible. The benign tumors of the submandibular gland is treated by simple excision with preservation of mandibular branch of the trigeminal nerve, the hypoglossal nerve, and the lingual nerve. Other benign tumors of minor salivary glands are treated similarly.

Malignant salivary tumors usually require wide local resection of the primary tumor. However, if complete resection cannot be achieved, adjuvant radiotherapy should be added to improve local control. This surgical treatment has many sequellae such as cranial nerve damage, Frey's syndrome, cosmetic problems, etc.

Usually about 44% of the patients have a complete histologic removal of the tumor and this refers to the most significant survival rate.

The clinical and pathology differential are different. From a pathology perspective, an endolymphatic sac tumor needs to be separated from metastatic renal cell carcinoma, metastatic thyroid papillary carcinoma, middle ear adenoma, paraganglioma, choroid plexus papilloma, middle ear adenocarcinoma, and ceruminous adenoma.

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.

It is important to exclude a tumor which is directly extending into the ear canal from the parotid salivary gland, especially when dealing with an adenoid cystic or mucoepidermoid carcinoma. This can be eliminated by clinical or imaging studies. Otherwise, the histologic differential diagnosis includes a ceruminous adenoma (a benign ceruminous gland tumor) or a neuroendocrine adenoma of the middle ear (middle ear adenoma).

Benign myoepithelioma are treated with simple excision. They are less prone to recurrence than pleomorphic adenoma.