Salivary Gland Tumors Oral Pathology and Surgery
1. Introduction
2. Anatomopathology of GS tumors
3. Clinical study
3.1. Tumors
3.1.1. Benign Epithelial Tumors: Adenomas
3.1.1.1. Pleomorphic adenoma or mixed tumor
3.1.1.2. Warthin tumor or cystadenolymphoma (CAL)
3.1.1.3. Basal cell adenoma
3.1.1.4. Oncocytic adenoma (oncocytoma)
3.1.2. Malignant epithelial tumors: Carcinomas.
3.1.2.1. Acinar cell carcinoma
3.1.2.2. Mucoepidermoid carcinoma
3.1.2.3. Adenoid cystic carcinoma = cylindroma
3.1.2.4. Carcinoma on pleomorphic adenoma
3.1.3. Non-lymphoid connective tissue tumors
3.1.4. Malignant lymphomas
3.1.5. Secondary tumors
3.2..Pseudotumors or salivary cysts
1. Introduction
Salivary gland tumors are relatively rare, however their ignorance can imply inappropriate and serious diagnostic and therapeutic behaviors. Their varied clinical presentation, the diverse possibilities of paraclinical investigation, the great diversity of anatomopathological forms and often complex surgical treatments dominate the interest in the study of these tumors.
In adults, salivary gland tumors are mainly located in the parotid gland (80% of tumors) and the submandibular gland (10 to 15%), while the sublingual gland and accessory salivary glands are rarely affected (5 to 10%).
Approximately 80% of parotid gland tumors and 50% of submandibular gland tumors are benign.
2. Anatomopathology of GS tumors
Anatomopathological knowledge of salivary gland tumors has progressed considerably. New techniques of immunohistochemistry, cytophotometry, hybridization techniques, tissue culture and chromosomal analysis have allowed the evolution of prognosis.
3. Clinical study
3.1. Tumors
3.1.1. Benign Epithelial Tumors or Adenomas
3.1.1.1. Pleomorphic adenoma or mixed tumor
a)clinic
- It is the most common salivary gland tumor (74%).
- Appears at all ages but especially between the 4th and 5th decade.
- It is a rounded or fusiform tumor, firm, regular and slowly growing and painless.
- Location: superficial lobe of the parotid gland (¾ of cases), the remaining 25% are located below
maxillary and accessory glands. Appears as a lump in front of or below the lobe (ear).
- No sensory or motor disorders.
- more or less mobilizable, never fixed
b) Anatomical pathology:
Macroscopy:
Nodular formation of a few mm to several cm in diameter, firm and not hard, with an appearance
whitish and translucent with the appearance of a false encapsulation which exposes the risk of
recurrence after limited excision.
Microscopy : characteristic structure.
Proliferation of epithelial and myoepithelial cells embedded in abundant stroma
myxoid and/or chondroid, hyaline or elastic, sometimes containing islands of adipose tissue or
bony.
c) Differential diagnosis:
- It is done with all benign subcutaneous tumors,
- With inflammatory lesions of the parotid gland,
- With tumor or inflammatory lesions of non-salivary tissues
- With parotid adenopathies,
- With vascular, nervous tumors, lipoma.
Salivary Gland Tumors Oral Pathology and Surgery
d) Additional examinations
Sialography : It shows a rounded lacuna in a normal parenchyma: “Ball in the hand” image.
Scintigraphy: does not fix technetium.
The puncture is strictly prohibited.
e) Evolution:
APs are very recurrent locally, especially in forms with abundant myxoid stroma and where there are breaches in the peripheral capsule. Cancerization is rare (5%) (10-15 years without treatment)
3.1.1.2. Warthin tumor or cystadenolymphoma (CAL)
a) Clinical study:
- It is a tumor of adults or elderly males.
- It is located at the level of the superficial lobe of the parotid gland.
- It is a tumor with imprecise contours and a liquid consistency.
- She may experience inflammatory flare-ups.
- There is never any facial paralysis.
- The differential diagnosis may be with lymphoepithelial cysts that are found associated with HIV infection.
- When cut, the tumor releases a brownish, viscous liquid.
b) Additional examinations
Sialography : Image of a lacuna + or – hemicircular and limited by efferent channels + or – packed on top of each other.
Scintigraphy : CAL captures technetium.
c) Anapath : Macroscopy: well-limited tumor with thick, stringy, brownish contents.
Microscopy: vegetation with double epithelial layer comprising cylindrical superficial cells, very irregularly arranged, and smaller basal cells.
Lymphoid tissue (+++) and clear centers are found. The superficial elements have a
enzymatic activity.
d. Particularities
The role of smoking has been highlighted by many authors.
Recently, an increase in the frequency of this tumor in women has been reported and could be explained by the increase in female smoking.
The identification of sex hormone receptors on the membrane of Warthin tumor cells could explain the observed hormonal dependence and an endocrine mechanism could control tumor growth.
e)/Treatment : enucleation
3.1.1.3. Basal cell adenoma
It is a rare tumor (1 to 2% of salivary gland tumors) occurring with a predilection age around 70 years, mainly affecting the parotid gland (70% of cases) and the accessory salivary glands of the upper lip (20% of cases).
There are four cell forms: solid, trabecular, tubular and membranous.
There is a risk of transformation into basal cell adenocarcinoma.
3.1.1.4. Oncocytic adenoma (oncocytoma)
a) Clinic:
Rare, it mainly affects elderly male subjects, located in the parotid gland.
There is no malignant transformation of these lesions.
b) Histology:
Proliferation of large cells with small nuclei and acidophilic cytoplasm, with many mitochondria.
c ) Differential diagnosis :
Especially with pleomorphic adenoma.
3.1.2. Malignant epithelial tumors: Carcinomas
There are a wide variety of salivary gland carcinomas but four forms dominate:
- acinar cell carcinoma,
- mucoepidermoid carcinoma,
- adenoid cystic carcinoma,
- carcinoma developed on pleomorphic adenoma.
Salivary Gland Tumors Oral Pathology and Surgery
3.1.2.1. Acinar cell carcinoma
It is mainly located in the parotid gland.
- Clinical
Especially in women, all ages are affected, peripheral facial paralysis may accompany the tumor. Metastases are most often disseminated by hematogenous route rather than by lymphatic route with a predominance towards the bone and the lung.
b) Anatomopathology
Macroscopically, the tumor is not encapsulated but is usually well circumscribed.
It can take on a solid or cystic appearance. Microscopic study shows that most of these tumors are infiltrating. They are formed of cells similar to the serous cells of the salivary glands, arranged in areas or acini, with cytoplasm provided with characteristic basophilic granules.
c) Treatment
Treatment is essentially surgical and radiotherapy appears to be of little effect.
3.1.2.2. Mucoepidermoid carcinoma
This tumor is the most common malignant tumor of the parotid gland and the second most common tumor of the submandibular gland.
a)Clinical : Approximately 8% of these tumors are associated with peripheral facial paralysis in low-grade forms of malignancy, and treatment is surgical, radiotherapy is not necessary. In high-grade forms of malignancy, the frequency of facial paralysis is around 25% and lymph node metastases exist in 50% of cases.
b) Anatomopathology
Macroscopically, the tumors are well circumscribed but not encapsulated.
Microscopy The tumor is characterized by the presence of epidermoid cells, mucous cells and intermediate cells. It may present a cystic formation containing a clear or colored substance and sometimes hemorrhagic.
c) treatment is most often based on a combination of surgery and radiotherapy .
3.1.2.3. Adenoid cystic carcinoma = cylindroma
It is a common tumor in both the parotid and submandibular areas and in accessory salivary glands.
a) Clinic
The tumor affects both sexes equally and the average age of discovery is between 40 and 60 years. Most of the time, the tumor appears as a salivary mass without clinical particularity. However, in 20% of cases, patients report paresthesia and in 30% of cases partial or total peripheral facial paralysis. This high percentage of facial paralysis is proof of the importance of the nervous extension of these tumors.
b) Anatomopathology
infiltrating tumor with three possible profiles: glandular, tubular and solid.
Perineural or perivascular invasion is very characteristic.
Solid tumors appear to have a poorer prognosis, while glandular or tubular tumors have a better prognosis.
C. Treatment is surgical excision
3.1.2.4. Carcinoma on pleomorphic adenoma
It is a tumor with clear signs of malignancy, such as cytological and histological features of anaplasia, abnormal mitoses, significant evolutivity and infiltration of neighboring tissues, and in which the presence of a pleomorphic adenoma is clear.
3.1.3. Non-lymphoid connective tissue tumors
These non-epithelial tumors represent barely 5% of salivary gland tumors.
About 90% of these tumors are benign.
– Benign tumors: by far the most frequent:
- lipomas: parotid++
- Angiomas: observed mainly in children, these are mainly lymphangiomas and
hemangiomas.
- Neuroma, neuroma, plexiform neuroma are sometimes observed in the context of the disease
- by Von Recklinghausen.
-Malignant tumors:
described exceptionally. These are rhabdomyosarcomas, malignant schwannomas or
melanomas.
3.1.4. Malignant lymphomas
Malignant lymphomas can be primary or include a more diffuse lymphoma of which salivary extension is only one part.
Malignant lymphomas of the salivary glands are usually associated with chronic immunosialadenitis such as Sjögren’s syndrome or benign lymphoepithelial lesions.
Most salivary gland lymphomas are non-Hodgkin lymphomas (85%) and should be classified according to the usual classification of lymphomas of this type.
3.1.5. Secondary tumors
This is most often a direct invasion of the gland by regional cancers.
Differentiating between a primary salivary gland tumor and intraglandular metastasis of an extrasalivary tumor is essential for treatment and prognosis.
3.2..Pseudotumors or salivary cysts
Mucoid cyst = mucocele.
True retentional cyst due to inflammatory or traumatic stenosis of an excretory duct or false cyst due to degeneration of the parenchyma.
- Especially at the lower lip level,
- Appears as a rounded or ovoid nodule, indolent, bluish-gray, renitent or fluctuant.
- At floor level it occupies the entire floor and becomes bilobed with evacuation of stringy liquid (egg white) after rupture.
The differential diagnosis is made with: Varicosity, angioma, dermoid cyst, thyroglossal tract cyst.
END
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