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.

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 most conclusive test for a patient with a potential neurofibrosarcoma is a tumor biopsy (taking a sample of cells directly from the tumor itself). MRIs, X-rays, CT scans, and bone scans can aid in locating a tumor and/or possible metastasis.

Imaging studies such as Computerized Tomography (CT) and Magnetic Resonance Imaging (MRI) can aid diagnosis. Medulloepithelioma appears isodense or hypodense with variable heterogeneity and calcification on non-contrast CT scan, and enhances with contrast. This radiographical finding is consistent with a primitive neuroectodermal tumour, especially in children. Blood studies and imaging studies of the abdomen may be used to detect metastases.

Needle aspiration biopsy can be used to aid diagnosis. Definitive diagnosis requires histopathological examination of surgically excised tumour tissues.

Histologically, medulloepithelioma resemble a primitive neural tube and with neuronal, glial and mesenchymal elements. Flexner-Wintersteiner rosettes may also be observed.

Immunohistochemically, neural tube-like structures are vimentin positive in the majority of medulloepitheliomas. Poorly differentiated medulloepitheliomas are vimentin negative.

Screening for melanoma in FAMMM kindreds should begin at age 10 with a baseline total body skin examination including scalp, eyes, oral mucosa, genital area, and nail, as family members may develop melanoma in their early teens.

At Mayo Clinic, FAMMM patients with a confirmed mutation and family history of pancreatic cancer are offered screening with either high-resolution pancreatic protocol CT, MRI, or endoscopic ultrasound starting at age 50 or 10 years younger than the earliest family member with pancreas cancer. They are counseled on the lack of evidence-based data to support screening, and on the limitations of our current technology to detect a lesion at a stage amenable to therapy.

Immunohistochemistry is performed as additional test. The strong positive expression of cytokeratin 19 was showed in primary SCTC, and negative in metastatic SCTC.

There are no specific radiological tests for SCTC verification. However these tests might be useful for identification of tumor borders and in planning of surgery.

If a patient displays congenital melanocytic nevi or giant congenital melanocytic nevi, the criteria for diagnosis of neurocutaneous melanosis is as follows:

- Melanocytic deposits exist within the central nervous system that are either malignant or benign

- The cutaneous lesions, giant or otherwise, are not malignant

This criteria is typically validated through biopsy of the cutaneous lesions and imaging of the central nervous system. It is important to establish that the cutaneous lesions are benign. If not, then the melanocytic deposits in the central nervous system may be the result of metastasis of cutaneous melanoma and not neurocutaneous melanosis.

Imaging has been shown to be the only reliable detection method for the presence of neurocutaneous melanosis that can be performed in living patients. Currently, the preferred imaging modality for diagnosis of neurocutaneous melanosis is Magnetic Resonance Imaging, although ultrasound is another viable option. The signal due melanin deposits in the leptomeninges typical of neurocutaneous melanosis can be easily detected in MRI scans of patients under four months old. In patients above this age, there is some suggestion that normal brain myelination may partially obscure these signals.

As most patients with neurocutaneous melanosis are asymptomatic, those who are diagnosed through MR imaging are not guarantied to develop symptoms. Those diagnosed who did not develop symptoms ranged from 10% to 68%. This wide range is most likely due to the large number of asymptomatic, undiagnosed patients with neurocutaneous melanosis.

Prenatal testing may be used to identify the existence of NF-1 in the fetus. For embryos produced via in vitro fertilisation, it is possible via preimplantation genetic diagnosis to screen for NF-1.

Chorionic villus sampling or amniocentesis can be used to detect NF-1 in the fetus.

People with NF-1 have a 50% percent chance of passing the disorder on to their kids, but people can have a child born with NF-1 when they themselves do not have it. This is caused in a spontaneous change in the genes during pregnancy.

The majority of patients with neurocutaneous melanosis are asymptomatic and therefore have a good prognosis with few complications. Most are not diagnosed, so definitive data in not available. For symptomatic patients, the prognosis is far worse. In patients without the presence of melanoma, more than 50% die within 3 years of displaying symptoms. While those with malignancy have a mortality rate of 77% with most patients displaying symptoms before the age of 2.

The presence of a Dandy-Walker malformation along with neurocutaneous melanosis, as occurs in 10% of symptomatic patients, further deteriorates prognosis. The median survival time for these patients is 6.5 months after becoming symptomatic.

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.

The primary method for treatment is surgical, not medical. Radiation and chemotherapy are not needed for benign lesions and are not effective for malignant lesions.

Benign granular cell tumors have a recurrence rate of 2% to 8% when resection margins are deemed clear of tumor infiltration. When the resection margins of a benign granular cell tumor are positive for tumor infiltration the recurrence rate is increased to 20%. Malignant lesions are aggressive and difficult to eradicate with surgery and have a recurrence rate of 32%.

Patient response to treatment will vary based on age, health, and the tolerance to medications and therapies.

Metastasis occurs in about 39% of patients, most commonly to the lung. Features associated with poor prognosis include a large primary tumor (over 5 cm across), high grade disease, co-existent neurofibromatosis, and the presence of metastases.

It is a rare tumor type, with a relatively poor prognosis in children.

In addition, MPNSTs are extremely threatening in NF1. In a 10-year institutional review for the treatment of chemotherapy for MPNST in NF1, which followed the cases of 1 per 2,500 in 3,300 live births, chemotherapy did not seem to reduce mortality, and its effectiveness should be questioned. Although with recent approaches with the molecular biology of MPNSTs, new therapies and prognostic factors are being examined.

The National Institutes of Health (NIH) has created specific criteria for the diagnosis of NF-1. Two of these seven "Cardinal Clinical Features" are required for positive diagnosis. There is practical flowchart to distinguish between NF1, NF2 and schwannomatosis.

- Six or more café-au-lait spots over 5 mm in greatest diameter in pre-pubertal individuals and over 15 mm in greatest diameter in post-pubertal individuals. Note that multiple café-au-lait spots alone are not a definitive diagnosis of NF-1 as these spots can be caused by a number of other conditions.

- Two or more neurofibromas of any type or 1 plexiform neurofibroma

- Freckling in the axillary (Crowe sign) or inguinal regions

- Optic glioma

- Two or more Lisch nodules (pigmented iris hamartomas)

- A distinctive osseous lesion such as sphenoid dysplasia, or thinning of the long bone cortex with or without pseudarthrosis.

- A first degree relative (parent, sibling, or offspring) with NF-1 by the above criteria.

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.

Radiologically

- Odontogenic Myxoma

- Ameloblastoma

- Central Giant Cell Granuloma

- Adenomatoid odontogenic tumor

Histologically

- Orthokeratocyst

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

- Unicystic ameloblastoma

With the symptoms above in mind, practitioners would likely look for decreased vision and intraocular masses in making their diagnosis as these have been documented as the most common findings for intraocular schwannomas. Additionally, these tumors are most frequently found in the choroid, at 60%, as compared to the ciliary body (40%) and the iris (11%). Schwannomas generally present themselves as smooth, ovoid masses, lacking pigmentation. However, these tumors can also rarely be colored and lobulated. This overlap can lead to a uveal melanoma diagnosis as these can be characteristics of both.

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.

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.

Dermal neurofibromas are not usually surgically removed unless they are painful or disfiguring, because there are generally so many of them and they are not dangerous.

CO lasers have been used to remove dermal neurofibromas. In a paper titled "Hypertrophic Scars After Therapy with CO Laser for Treatment of Multiple Cutaneous Neurofibromas" Ostertag et al. said this about treatment by laser: “The cosmetic disfigurement is the most important issue in the decision to treat cutaneous symptoms of neurofibromatosis. Treating patients with extensive neurofibromas with [a] CO laser is still the best choice. However, it is strongly advised that a test treatment be performed to judge the effectiveness of the procedure and whether the developed scar is an acceptable trade-off.”

A study by You et al. was only able to evaluate the 47 documented cases that have been made to date. According to this study, intraocular schwannomas are more prevalent in females as compared to males with a ratio of 3:1. Additionally, individuals are more likely to present with intraocular schwannomas at a younger age than with uveal melanomas, the most common intraocular tumor. According to the participants evaluated in this study, the average age of occurrence was 37 years old, however, it is important to note that the age range documented represented individuals 9–76 years old.

PECs typically stain for melanocytic markers (HMB-45, Melan A (Mart 1), Mitf) and myogenic markers (actin, myosin, calponin).

A blood test for protein melanoma inhibitory activity may be used to detect the presence of neurofibromas.

Total resection of the tumour, followed by radiation therapy is the standard treatment modality. Medulloepithelioma of the ciliary body may necessitate enucleation of the eye. Radiation therapy alone may prolong survival. Aggressive chemotherapy with autologous bone marrow transplant is used for metastatic medulloepitheliomas.

There are three diagnostic criteria proposed:

1. the tumor arises along a peripheral nerve, or in a ganglioneuroma, or in a patient with neurofibromatosis type 1 (NF1), or has a metastatic character

2. the growth characteristics of the tumor is typical for a Schwann cell tumor

3. rhabdomyoblasts arise within the body of the tumor.