Oncocytoma

 Oncocytoma 

  Definition 

  Oncocytoma is a benign salivary gland tumor composed of large epithelial cells known as oncocytes. 

  Oncocytes occur as a result of focal oncocytic metaplasia of salivary ductal and acinar cells which is a common finding in old age (above 50 years). 
  
  Histogenesis 

  It originates from oncocytes. 

  Clinical features 

  It is a tumor of old age (after the 6th decade of life). 

  More common in the major salivary glands especially the parotid gland.  

  It appears as a , slowly growing, painless, movable mass that rarely exceeds 4 cm in diameter. 

  Histopathologic features 

  It is a well-circumscribed tumor that is composed of sheets of large polyhedral cells (oncocytes),  

  The cells have granular eosinophilic cytoplasm with centrally located nuclei. 

(The granular cytoplasm is due to excessive accumulation of  mitochondria). 
 activity.

Sjogren’s syndrome

Sjogren’s  syndrome 

  Definition

  Sjogren’s syndrome is a chronic, systemic autoimmune inflammatory disease that principally involves salivary and lacrimal glands resulting in xerostomia (dry mouth) and xerophthalmia (dry eyes).

  Presentation of both xerostomia and xerophthalmia is known as  sicca syndrome  (Sicca means dry).

  Forms of the disease 

A) Primary Sjogren’s syndrome  (sicca syndrome alone, no other autoimmune disorder is present).

B)  Secondary Sjogren’s  syndrome
The patient manifests sicca syndrome  in addition to another autoimmune disease as rheumatoid arthritis.

  Clinically 

  Mostly affects  middle-aged adult femals. 

A)  Eye manifestations: 

Dryness, redness, burning sensation of eyes and sensation of presence of a
foreign body in the eye  (The effects on the eye often are called
keratoconjunctivitis sicca).

B)  Oral manifestations: 

1. Xerostomia.
2. Difficulty in swallowing.
3. Altered taste.
4. The tongue often becomes fissured and exhibits atrophy of the papillae.
5. The oral mucosa is dry and may be red and tender (usually as a result of  candidiasis).
6. Difficulty in wearing dentures.
7. Increased risk for dental caries (especially cervical caries).

C)  Enlargement of the major salivary glands
: 
Swelling is usually diffuse, firm and  bilateral.  It may be non painful or slightly tender.

  Radiograghic examination (Sialography) 

  Punctate sialectasia demonstrating a "fruit-laden, branchless tree" .    
  This is due to leakage of contrast material through the duct wall reflecting significant ductal and acinar damage.

  Histopathologic features 

  Lymphocytic infiltration of the salivary gland with disrtuction of the acini.
  proliferation of some duct tissue forming epimyoepithelial islands.
  There is a great risk of malignant  transformation  to lymphoma (more common in primary Sjogren).

Xerostomia 

  Xerostomia means dry mouth

  Causes  
1.  Developmental (salivary gland aplasia).
2.  Loss of body fluids as:
-  Impaired fluid intake.
-  Hemorrhage.
-  Vomiting and diarrhea.
3.  Medications as antihistamines and antidepressants.
4.  Radiation therapy to the head and neck.
5.  Systemic diseases as Sjogren’s syndrome and diabetes.
6.  Local factors as smoking and mouth breathing.

  Clinical features 

1.  Reduction in salivary secretion.
2.  Difficulty with mastication and swallowing.
3.  The mucosa appears dry.
4.  Poor retention of dentures.
5.  The dorsal tongue often is fissured with atrophy of the filiform papillae.
6.  Predisposition to infection as  oral candidiasis  (because of the reduction in the cleansing and antimicrobial activity of the saliva).
7.   Increased risk for dental caries (especially cervical caries).


 

Mucoepidermoid carcinoma

  Mucoepidermoid carcinoma 

  Definition
  
  The mucoepidermoid carcinoma is one of  the most common salivary gland malignancies.  

  Histogenesis 
  
  It origenates  from  excretory duct epithelium. 

  Clinical features 

  Occurs most commonly in the parotid gland. 
  The palate is the most common intraoral site. 
  Low grade neoplasms appear as benign tumors. 
  High grade neoplasms appears as:  
-     Painful, rapidly growing mass. 
-    The tumor  is fixed  to underlying tissues (when tumor cells infiltrate the surrounding structures). 
- Facial nerve paralysis (if the neoplasm affects the parotid). 
- Ulceration. 
  Neoplasms of minor salivary glands appears as:  
-  Swelling or ulcerated mass. 
-  Swelling may be fluctuant and have a blue color (resemble mucocele). 
-  It is painless in early stages. 
-  May affects the palate, buccal mucosa, tongue or lip. 

  Histopathologic features 

  Mucoepidermoid carcinoma is composed of a mixture of : 
-  Mucous – producing cells. 
-  Squamous ( epidermoid ) cells.  
-  Intermediate cell , which is believed to be a progenitor of both the mucous and the epidermoid cells. 
  The mucous – secreting cells are , 
-  cubical or  columnar with foamy cytoplasm. 
-  They tend to line the cystic spaces , or  arranged in solid  sheets .  
  The epidermoid cells  , 
-  Form solid sheets or line the cystic spaces.  
-  These cells are of squamous epithelial type having a polygonal shape . 
  Intermediate cells are smaller than either mucous or epidermoid cells . They appear as small basaloid cells. 

   Low-grade tumors show: 

-  High proportion of mucous cells, prominent cyst formation, minimal cellular atypia. 

  High-grade tumors show:  

-  High proportion of solid sheets of squamous and intermediate cells.  
-  cells demonstrate considerable pleomorphism, and mitotic activity. 
-  few cystic spaces. 

  Intermediate-grade tumors show: 
-  Features between those of the low-grade and high-grade neoplasms. 
  
  NB

  Intraosseous mucoepidermoid carcinomas (central mucoepidermoid carcinomas) may develop as a result of: Neoplastic transformation of the lining of a dentigerous cyst (odontogenic 
epithelium). 

Adenoid cystic carcinoma

Adenoid cystic carcinoma  

  Definition  

  Adenoid cystic carcinoma is one of the common salivary gland malignancy.  Because of its distinctive histopathologic features, it was originally called a "cylindroma”.   The use of the term cylindroma should be avoided because it does not denote the malignant nature of the tumor and because the same term is used for a benign skin tumor.  

  Clinical features 

  The adenoid cystic carcinoma can occur in any salivary gland site, but it occurs most commonly in the minor salivary gland.  

  The palate is the most common site.  

  It appears as a slowly growing mass. 

  Pain is a common and important finding, and may occur early in the course of the disease (due to perineural invasion).  

  Facial nerve paralysis (if the neoplasm affects the parotid). 

  Palatal tumors often are ulcerated.  

   Histogenesis  

  Adenoid Cystic Carcinoma originate from intercalated duct cells and myoepithelial cells. 

  Histopathologic features  

  The adenoid cystic carcinoma is composed of a mixture of myoepithelial cells and ductal cells. 

  The ductal cells are small and cuboidal, with deeply basophilic nuclei and little cytoplasm. 

  Myoepithelial cells have clear cytoplasm and darkly staining angular nuclei. 

  Three histopathologic patterns are recognized: 
(1) cribriform , (2) tubular, and (3) solid.  

(1) Cribriform pattern  

  Is the most common pattern. 
  It is characterized by islands of basaloid epithelial cells that contain multiple cystic spaces resembling swiss cheese.  
  These spaces often contain basophilic mucoid material.  

(2) Tubular pattern  
  The tumor cells occur as multiple small ducts or tubules within a hyalinized stroma.  
  The duct like spaces are lined by an inner row of cuboidal epithelial cells and an outer zone of myoepithelial cells. 

(3) Solid pattern  
  It consists of large islands or sheets of cuboidal epithelial cells.  
  This type may  also show more pleomorphism and mitotic activity than the other forms. 
  This type is the most aggressive type. 


  
  

Bacterial Infection of Salivary Glands

Bacterial Infection of Salivary Glands 

        1. Acute bacterial sialadenitis. 

        2. Chronic sialadenitis. 


                                 1.   Acute bacterial sialadenitis 

•        Causes 

             Ductal  obstruction can be caused by  sialolithiasis, congenital  strictures, or compression by an adjacent tumor.

             Decreased salivary flow can result from dehydration, debilitation or medications.

             Recent   surgery   because   the   patient   has  been   kept   without   food   or   fluids   and   has

                received medications that produce xerostomia.

•      Type of involved bacteria 

             Most cases are due to Staphylococcus aureus.

             They also may arise from streptococci or other organisms.

             The organism reach the gland from the oral cavity through the duct.

•       Clinically 

             Most common in the parotid gland and may be  bilateral (acute suppurative parotitis).

             The  affected gland is swollen and painful  and  the overlying  skin may be erythematous.

             Low-grade fever may be present.

             Trismus.

             A purulent discharge  often  is  observed  from the duct orifice when applying  digital  pressure.

•  Histopathologic features 

             Accumulation of neutrophils is observed within the ductal system and acini.

                               2. Chronic sialadenitis 

     Recurrent or persistent ductal obstruction (most commonly caused by sialoliths) can lead to

        a chronic sialadenitis.

•     Clinically 

             Periodic swelling and pain occur within the affected gland.

             Swelling usually develop at meal time when salivary flow is stimulated.

             Chronic sialadenitis can affect the parotid gland, submandibular gland, or the minor  salivary                            glands.

•   Histopathologic features 

             Accumulation of chronic inflammatory cells (lymphocytes and plasma cells) within

                the ductal system and acini.

             Atrophy of the acini is common.

             Salivary gland fibrosis may occur.

1. 
   

Squamous cell carcinoma

          Squamous cell carcinoma

         Definition

                A malignant neoplasm of squamous epithelium.

                It constitutes 95% of oral cancers.

         Etiology

             1.  Tobacco  and  alcohol  are  the  most  common associations  (Tobacco   chewing   or

                 smoking).

             2.   Leukoplakia and Erythroplakia.

             3.  Oncogenic viruses as, Human papilloma virus, Herpes simplex virus, Epstein –Barr  virus.

             4.  Candidal infection.

             5.  Syphilis.

             6.  Genetic factors.

             7.  Exposure to ultra-violet light (cancer of the lip), or exposure to x-ray.

             8.  Iron deficiency and vitamin deficiency ( A and B).

          Clinical Features

              Site:

                    a)  Lip

                    b)  Tongue

                    c)  Floor of the mouth

                    d)  Gingiva

                    e)  Buccal mucosa

                    f)  Palate

                 Ages & sex : old Men (50-60 years).

              Symptoms: usually asymptomatic, but pain may occur with deep invasion.

              Shape: oral squamous cell carcinoma  of  any site has a varied clinical presentation and can arise                   as:

                        1.  Exophytic mass:

                            -Papillary or virrocous, indurated mass (feel hard on palpation),

                            -The   color   vary   from   normal   to   red   to   white   (depending on amount of

                            keratinization or vascularity).

                        2.  Endophytic growth:

                             - Non-healing ulcer.

                             - Has raised rolled, everted margin,indurated base and  necrotic floor.

                       3.   Leukoplakic (white patch).

                        4.  Erythroplakic (red patch).

                        5.  Erythro-Leukoplakic.

                         a.   Squamous cell carcinoma of lip

           Mostly on the lower lip (exposed to ultraviolet radiation).

           Common at the site where the patient hold pipe,cigar or cigarette, due to

               combustion end products of tobacco.

           Metastasis is late to submental lymph node.

           Has a favorable prognosis (as it is visible).

                         b.   Squamous cell carcinoma of the tongue

             Account for more than 50% of oral cancer (most common intraoral site).

             Mostly found on the posterior lateral border of the tongue.

             In advanced lesions with invasion of the surrounding tissue,there is:

                 -   Immobility of the tongue.

                 -   Altered speech.

                 -   Difficulty in swallowing (dysphagia).

             Metastasis is early to the submandibular and deep cervical lymph nodes.

             Has poor prognosis as it is difficult to visualize and tongue is rich in lymphatic

               vessels.

Median Rhomboid Glossitis

 Median Rhomboid Glossitis 

Definition 

     Central erythematous zone of the tongue due to a chronic fungal infection.

     The erythema is due to atrophy of the filiform papillae.

     In the   past   this was  thought to be a developmental  defect of the tongue  resulted from a failure of the tuberculum impar to be covered by the lateral processes of the tongue.

Clinical features 

     Ovoid or diamond, depapillated, erythematous zone.

     Smooth, raised, and asymptomatic.

     It  affects the midline of  posterior dorsal surface  of tongue   just   anterior   to   the foramen
       cecum.