The definitive diagnosis is by histologic analysis, i.e. and examination under the microscope.

Under the microscope, OKCs vaguely resemble keratinized squamous epithelium; however, they lack rete ridges and often have an artifactual separation from their basement membrane.

On a CT scan, The radiodensity of a keratocystic odontogenic tumour is about 30 Hounsfield units, which is about the same as ameloblastomas. Yet, ameloblastomas show more bone expansion and seldom show high density areas.

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).

No pathognomonic clinical signs for TSC complex are seen. Many signs are present in individuals who are healthy (although rarely), or who have another disease. In order to meet diagnostic criteria for TSC complex, an individual must either have: 1) Two or more major criteria; or 2) One major criterion along with two or more minor criteria.

In infants, the first clue is often the presence of seizures, delayed development, or white patches on the skin. A full clinical diagnosis involves:

- Taking a personal and family history

- Examining the skin under a Wood's lamp (hypomelanotic macules), the fingers and toes (ungual fibroma), the face (angiofibromas), and the mouth (dental pits and gingival fibromas)

- Cranial imaging with nonenhanced CT or, preferably, MRI (cortical tubers and subependymal nodules)

- Renal ultrasound (angiomyolipoma or cysts)

- An echocardiogram in infants (rhabdomyoma)

- Fundoscopy (retinal nodular hamartomas or achromic patch)

The various signs are then marked against the diagnostic criteria to produce a level of diagnostic certainty:

- Definite – either two major features or one major feature plus two minor features

- Probable – one major plus one minor feature

- Suspect – either one major feature or two or more minor features

Due to the wide variety of mutations leading to TSC, no simple genetic tests are available to identify new cases, nor are any biochemical markers known for the gene defects. However, once a person has been clinically diagnosed, the genetic mutation can usually be found. The search is time-consuming and has a 15% failure rate, which is thought to be due to somatic mosaicism. If successful, this information can be used to identify affected family members, including prenatal diagnosis. , preimplantation diagnosis is not widely available.

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

Radiologically

- Odontogenic Myxoma

- Ameloblastoma

- Central Giant Cell Granuloma

- Adenomatoid odontogenic tumor

Histologically

- Orthokeratocyst

- Radicular cyst (particularly if the OKC is very inflamed)

- Unicystic ameloblastoma

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

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.

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.

Lesions of the nipple and areola, such as nipple adenoma, may be difficult to image clearly on routine mammogram or ultrasonography. Nipple adenomas can be imaged using magnetic resonance imaging (MRI) and conventional or MR ductogram.

Serous cystic neoplasms can come to clinical attention in a variety of ways. The most common symptoms are very non-specific and include abdominal pain, nausea and vomiting. In contrast to many of the other tumors of the pancreas, patients rarely develop jaundice (a yellowing of the skin and eyes caused by obstruction of the bile duct), or weight loss. These signs and symptoms are not specific for a serous cystic neoplasm, making it more difficult to establish a diagnosis. Doctors will therefore often order additional tests.

Once a doctor has reason to believe that a patient may have serous cystic neoplasm, he or she can confirm that suspicion using one of a number of imaging techniques. These include computerized tomography (CT), endoscopic ultrasound (EUS), and magnetic resonance cholangiopancreatography (MRCP). These tests will reveal a cystic mass within the pancreas. The cysts do not communicate with the larger pancreatic ducts. In some cases a fine needle aspiration (FNA) biopsy can be obtained to confirm the diagnosis. Fine needle aspiration biopsy can be performed through an endoscope at the time of endoscopic ultrasound, or it can be performed through the skin using a needle guided by ultrasound or CT scanning.

A growing number of patients are now being diagnosed before they develop symptoms (asymptomatic patients). In these cases, the lesion in the pancreas is discovered accidentally (by chance) when the patient is being scanned (x-rayed) for another reason.

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.

The tumor must be removed with as complete a surgical excision as possible. In nearly all cases, the ossicular chain must be included if recurrences are to be avoided. Due to the anatomic site of involvement, facial nerve paralysis and/or paresthesias may be seen or develop; this is probably due to mass effect rather than nerve invasion. In a few cases, reconstructive surgery may be required. Since this is a benign tumor, no radiation is required. Patients experience an excellent long term outcome, although recurrences can be seen (up to 15%), especially if the ossicular chain is not removed. Although controversial, metastases are not seen in this tumor. There are reports of disease in the neck lymph nodes, but these patients have also had other diseases or multiple surgeries, such that it may represent iatrogenic disease.

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.

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.

Metanephric adenoma is diagnosed histologically. The tumours can be located at upper pole, lower pole and mid-hilar region of the kidney; they are well circumscribed but unencapsulated, tan pink, with possible cystic and hemorrhagic foci. They show a uniform architecture of closely packed acinar or tubular structures of mature and bland appearance with scanty interposed stroma. Cells are small with dark staining nuclei and inconspicuous nucleoli. Blastema is absent whereas calcospherites may be present. Glomeruloid figures are a striking finding, reminiscent of early fetal metenephric tissue. The lumen of the acini may contain otherwise epithelial infoldings or fibrillary material but it is quite often empty. Mitoses are conspicuously absent.

In the series reported by Jones "et al." tumour cells were reactive for Leu7 in 3 cases of 5, to vimentine in 4 of 6, to cytocheratin in 2 of 6, to epithelial membrane antigen in 1 of 6 cases and muscle specific antigen in 1 of 6.

Olgac "et al." found that intense and diffuse immunoreactivity for alpha-methylacyl-CoA racemase (AMACR) is useful in differentiating renal cell carcinoma from MA but a panel including AMACR, CK7 and CD57 is better in this differential diagnosis.

Differential diagnosis may be quite difficult indeed as exemplified by the three malignancies initially diagnosed as MA that later metastasized, in the report by Pins et al.

In terms of diagnosing Bannayan–Riley–Ruvalcaba syndrome there is no current method outside the physical characteristics that may be present as signs/symptoms. There are, however, multiple molecular genetics tests (and cytogenetic test) to determine Bannayan–Riley–Ruvalcaba syndrome.

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.

Wide, radical, complete surgical excision is the treatment of choice, with free surgical margins to achieve the best outcome and lowest chance of recurrence. Radiation is only used for palliation. In general, there is a good prognosis, although approximately 50% of patients die from disease within 3–10 years of presentation.

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

The appropriate treatment in contemporary western medicine is complete surgical excision of the abnormal growth with a small amount of normal surrounding breast tissue.

In terms of treatment/management one should observe what signs or symptoms are present and therefore treat those as there is no other current guideline. The affected individual should be monitored for cancer of:

- Thyroid

- Breast

- Renal

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

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.

The lesion presents in young patients, so the differential for a "polyp", especially when the lymphoid component is crushed or dominant, would include a rhabdomyosarcoma, extramedullary plasmacytoma, and a neuroendocrine adenoma of the middle ear.

Complete removal of a SSA is considered curative.

Several SSAs confer a higher risk of subsequently finding colorectal cancer and warrant more frequent surveillance. The surveillance guidelines are the same as for other colonic adenomas. The surveillance interval is dependent on (1) the number of adenomas, (2) the size of the adenomas, and (3) the presence of high-grade microscopic features.