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).

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.

Radiologically

- Odontogenic Myxoma

- Ameloblastoma

- Central Giant Cell Granuloma

- Adenomatoid odontogenic tumor

Histologically

- Orthokeratocyst

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

- Unicystic ameloblastoma

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.

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.

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.

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.

They are benign lesions and malignant degeneration is rare. They are usually treated with curettage which however have a high recurrence rate of 25%. As such if an en-bloc resection is possible this is advisable

The treatment is simple excision and exclusion of a malignant neoplasm.

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.

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

Intraductal papillary mucinous neoplasms can come to clinical attention in a variety of different ways. The most common symptoms include abdominal pain, nausea and vomiting. The most common signs patients have when they come to medical attention include jaundice (a yellowing of the skin and eyes caused by obstruction of the bile duct), weight loss, and acute pancreatitis. These signs and symptoms are not specific for an intraductal papillary mucinous 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 an intraductal papillary mucinous 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 dilatation of the pancreatic duct or one of the branches of the pancreatic duct. 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.

IPMN forms cysts (small cavities or spaces) in the pancreas. These cysts are visible in CT scans (X-ray computed tomography). However, many pancreatic cysts are benign (see Pancreatic disease).

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 (i.e. undergoing an ultrasound, CT or MRI scan) for another reason. Up to 6% of patients undergoing pancreatic resection did so for treatment of incidental IPMNs.

In 2011, scientists at Johns Hopkins reported that they have developed a gene-based test that can be used to distinguish harmless from precancerous pancreatic cysts. The test may eventually help patients with harmless cysts avoid needless surgery. Bert Vogelstein and his colleagues discovered that almost all of the precancerous cysts (intraductal papillary mucinous neoplasms) of the pancreas have mutations in the KRAS and/or the GNAS gene. The researchers then tested a total of 132 intraductal papillary mucinous neoplasms for mutations in KRAS and GNAS. Nearly all (127) had mutations in GNAS, KRAS or both. Next, the investigators tested harmless cysts such as serous cystadenomas, and the harmless cysts did not have GNAS or KRAS mutations. Larger numbers of patients must be studied before the gene-based test can be widely offered.

Small unilocular lesions have been successfully treated with enucleation and curettage followed by chemical bone cautery. Multilocular tumors exhibit a 25% recurrence rate and, therefore, must be treated more aggressively. In the case of a multilocular myxoma, resection of the tumor with a generous portion of surrounding bone is required. Because of the gelatinous nature of the tumor, it is crucial for the surgeon to remove the lesion intact so as to further reduce the risk of recurrence.

Plain film

often seen as a lobulated, eccentric radiolucent lesion

long axis parallel to long axis of long bone

no periosteal reaction (unless a complicating fracture present)

geographic bone destruction: almost 100%

well defined sclerotic margin: 86%

there can be presence of septations (pseudotrabeculation): 57% 2

there can be presence of matrix calcification in a small proportion of cases: 12.5%1

MRI

MR features are often not particularly specific. Signal characteristics include

T1 - low signal

T1 C+ (Gd) -

the majority (~70%) tend to show peripheral nodular enhancement

~ 30% diffuse contrast enhancement and this can be either homogeneous or heterogeneous 19

T2 - high signal

Bone scan

A scintigraphic "doughnut sign" has been described in this tumour type 11. However, this is very non-specific and can be found in a plethora of other bone lesions.

Complete surgical excision is the treatment of choice, associated with an excellent long term clinical outcome.

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.

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

Surgical excision of the lesion is done, and depending upon the clinical circumstances, this may or may not involve removal of the involved tooth. With incomplete removal, recurrence is common; some surgeons advocate curettage after extraction of teeth to decrease the overall rate of recurrence.

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.

Treatment consists of wide resection or amputation. Metastases are rare at presentation but may occur in up to 30% of patients during the disease course. Prognosis is excellent, with overall survival of 85% at 10 years, but is lower when wide surgical margins cannot be obtained. This tumor is insensitive to radiation so chemotherapy is not typically used unless the cancer has metastasized to the lungs or other organs.

Recurrence is common, although the recurrence rates for block resection followed by bone graft are lower than those of enucleation and curettage. Follicular variants appear to recur more than plexiform variants. Unicystic tumors recur less frequently than "non-unicystic" tumors. Persistent follow-up examination is essential for managing ameloblastoma. Follow up should occur at regular intervals for at least 10 years. Follow up is important, because 50% of all recurrences occur within 5 years postoperatively. Recurrence within a bone graft (following resection of the original tumor) does occur, but is less common. Seeding to the bone graft is suspected as a cause of recurrence. The recurrences in these cases seem to stem from the soft tissues, especially the adjacent periosteum. Recurrence has been reported to occur as many as 36 years after treatment.

To reduce the likelihood of recurrence within grafted bone, meticulous surgery with attention to the adjacent soft tissues is required.

Surgical excision is the preferred method of treatment for benign glomus tumors.

Diagnosis of EIN lesions is of clinical importance because of the increased risk of coexisting (39% of women with EIN will be diagnosed with carcinoma within one year) or future (the long term endometrial cancer risk is 45 times greater for a woman with EIN compared to one with only a benign endometrial histology) endometrial cancer. Diagnostic terminology is that used by pathologists, physicians who diagnose human disease by examination of histologic preparations of excised tissues. Critical distinctions in EIN diagnosis are separation from benign conditions such as benign endometrial hyperplasia (a field effect in endometrial tissue caused by excessive stimulation by the hormone estrogen), and cancer.

The spectrum of disease which must be distinguished from EIN (Table II) includes benign endometrial hyperplasia and carcinoma:

Table II: Disease classes that need to be distinguished from EIN.

EIN may be diagnosed by a trained pathologist by examination of tissue sections of the endometrium. All of the following diagnostic criteria must be met in a single area of one tissue fragment to make the diagnosis (Table III).

Table III: EIN diagnosis.

It is important to separate hiberoma from adult rhabdomyoma, a granular cell tumor and a true liposarcoma.