Salivary Gland Diseases PDF

Salivary gland diseases Dr. Deena Esmat A.Elhameed BDS, MFD Royal college IRELAND MD Oral Pathology & Forensic Odontology SMSB  Salivary glands Salivary Glands are exocrine glands Their secretion (saliva) flow into the oral cavity through their Ducts. They are ectoder...

Salivary gland diseases Dr. Deena Esmat A.Elhameed BDS, MFD Royal college IRELAND MD Oral Pathology & Forensic Odontology SMSB  Salivary glands Salivary Glands are exocrine glands Their secretion (saliva) flow into the oral cavity through their Ducts. They are ectodermal in origin. Three paired major glands: the parotid, the submandibular and the sublingual and minor seromucous glands that are distributed throughout the Sino-nasal tract, oral cavity, pharynx, larynx and lower respiratory tract (trachea and lungs).  The minor salivary glands secrete continuously. while the major glands secrete mainly as a response through parasympathetic activity induced by stimuli. The parotid glands are almost entirely serous. The sublingual glands are predominantly mucous. the submandibular glands contain both serous and mucous. Composition of saliva Human saliva is 99.5%water. but it contains many important substances, (other 0.5%) including electrolytes, mucus, antibacterial compounds and various enzymes as amylase (an enzyme that breaks down starch ). Electrolytes: sodium, potassium, calcium, magnesium, chloride, bicarbonate and phosphate Classification of salivary glands diseases  Acute Bacterial bacterial infection sialadenitis. of salivary glands Chronic sialadenitis  Acute bacterial sialadenitis. Causes: Recent abdominal surgery because the patient has been kept without food or fluids and has received medications that produce xerostomia (as atropine). Decreased salivary flow because of dehydration, debilitation. Type of involved bacteria: Most cases are due to Staphylococcus aureus, Streptococcus viridans and Pneumococci. Pathogenesis: The normal flow of saliva through the duct prevents oral bacteria from ascending the duct to cause infection. Diminution of salivary flow enables the organism reach the gland from the oral cavity through the duct (ascending infection, from the oral cavity)  Acute bacterial sialadenitis Clinically: 1.Most common in the parotid gland and may be bilateral in 10-25% of cases. (acute suppurative parotitis). 2.The affected gland is swollen and painful uplifting of the lobe of the ear if the parotid is affected. The overlying skin may be erythematous. 3.Low-grade fever may be present. 4.Elevated erythrocyte sedimentation rate and leukocytosis. 5.Trismus. 6.A purulent discharge often is observed from the duct orifice when applying digital pressure. 7. General malaise and headache. 8.Oedema may spread to involve the cheek, periorbital region and neck.  Histopathologic features The earliest change is catarrhal inflammation (inflammation that result in a thick exudate of mucous and neutrophils). If neglected, It will turn into a purulent exudate with abscesses formation and varying degrees of acinar destruction. Accumulation of neutrophils is observed within the ductal system, periductal tissues and acini. Treatment The treatment of acute sialadenitis includes appropriate antibiotic therapy and rehydration of the patient to stimulate salivary flow. Maintain good oral hygiene. Surgical drainage may be needed if there is abscess formation. Chronic sialadenitis Causes Bacterial infection in case of Recurrent or persistent ductal obstruction caused by sialolithiasis, compression by an adjacent tumor. Noninfectious causes include Radiation therapy and Sjogren syndrome( Immunologic disorder). Chronic sialadenitis Clinically It usually starts as acute parotitis(may be bilateral). Pain subsides within a few days. Duct orifice is inflamed and flow of saliva decreases. Swelling of the affected gland may persist for weeks or months. Recurrent swelling and pain may occur within the affected gland especially at mealtime (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. Ductal dilatation and hyperplasia of the lining epithelium with various metaplasia (squamous, mucous, oncocytic). Goblet cell metaplasia produces abundant mucin. Salivary gland cysts 1.Mucus 2. Mucous extravasation retention cyst cyst (pseudo (true cyst ) cyst). Mucous retention cyst It is a true cyst caused by obstruction due to a stone which results in a dilation that is lined by epithelium. Occasionally periductal scar or a tumor may cause the ductal obstruction  Histopathology Epithelial lining: Compressed ductal epithelium ranging from cuboidal, columnar, pseudo stratified to stratified squamous. Connective tissue wall is minimally inflamed. Lumen of the cyst contains mucin. Mucus extravasation cyst It is pseudo cyst as there is no epithelial lining. Etiology and pathogenesis Trauma to salivary gland excretory duct as biting the lip or pinching the lip by extraction forceps leading to rupture of duct and escape or extravasation of mucin into the surrounding connective tissues Clinical Features Mucocele: minor salivary gland. Ranula: in the sublingual gland. Sialocele: in the parotid gland & submandibular  Histopathology An area of spilled mucin surrounded by a granulation tissue that is infiltrated by inflammatory cells usually includes neutrophils and macrophages lymphocytes and plasma cells. (Extravasation of mucin is an inflammatory reaction followed by connective tissue repair). Clinical differential diagnosis of mucus extravasation cyst: 1. Mucus retention cyst 2. Salivary gland neoplasms. 3. Vascular malformation. 4. Benign connective tissue neoplasms. Obstructive salivary gland disease (Sialolithiasis)(salivary duct calculus) Sialoliths are calcified structures that develop within the salivary ductal system. They arise from deposition of calcium salts (calcium phosphates and carbonates)around: thicken mucus, micro-organisms, desquamated ductal epithelial cells or foreign body. Chronic sialadenitis may Promote the formation of duct stone. Clinically Most often develop within the ductal system of the submandibular gland (due to the long, tortuous, upward path of the duct and the thicker, mucoid secretions). It occurs less frequently within the parotid gland or minor salivary glands. The stone may be in the gland, in the duct or in both. Periodic swelling and pain occur within the affected gland. Swelling usually develop at mealtime. If the stone is located toward the terminal portion of the duct, a hard mass may be palpated beneath the mucosa that have a yellowish color. Histologically A decalcified stone is seen to consist of an amorphous, concentrically laminated material. This surrounds a core of micro-organisms, epithelial cells or a foreign body Radiographically Appear as radiopaque mass. Treatment Small sialoliths of the major glands sometimes can be treated conservatively by gentle massage of the gland to bring the stone toward the duct orifice. Larger sialoliths usually need to be removed surgically. If significant inflammatory damage has occurred within the gland, and in case of minor gland sialoliths, the gland may need to be removed.  Autoimmune salivary gland disease 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) PATHOGENESIS Circulating autoantibodies and the infiltrating lymphocytes activated. appear to be immunologically activated. However, a recent report of viral infection(coxsackie) virus may also play a role in the pathogenesis of SS. There is stimulation and intense activity of mainly B cells. Sjogren’s syndrome Two 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 and systemic lupus erythematosus). Sjogren’s syndrome Diagnosis: Careful clinical examination. Stimulated parotid salivary flow rates are measured. (Normal salivary is between 1 and 2 ml per minute but may be reduced to 0.5 ml/mm). Sialography, CT OR MRI Lab test Histopathology Clinically Mostly affects middle-aged adult females. 1) 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 kerato conjunctivitis sicca) 2) Oral manifestations: Xerostomia. Difficulty in swallowing. Altered taste. The tongue often becomes fissured and exhibits atrophy of the papillae. The oral mucosa is dry and may be red and tender (usually because of candidiasis). Difficulty in wearing dentures. Increased risk for dental caries (especially cervical) Clinically 3) Enlargement of the major salivary glands: swelling is usually :diffuse, firm, bilateral may be non painful or slightly tender. Radiographic examination (Sialography) demonstrating a "cherry blossom, or fruit- laden, branchless tree" Or Snowflake pattern. This is due to leakage of contrast material through the duct wall reflecting significant ductal and acinar damage Laboratory findings ❖Numerous auto-antibodies may be found, including: Anti-nuclear antibodies (in secondary Sjogren) Rheumatoid factor, (in secondary Sjogren) Anti-Sjogren’s syndrome-A (SS-A) Anti-Sjogren’s syndrome-B (SS-B). ❖Antibodies SS-A and SS-B may be seen in association with both primary and secondary Sjogren's syndrome. ❖Increase ESR (erythrocyte sedimentation rate) ❖Increase IgG  Histopathologic Features Lymphocytic infiltration of the salivary gland with destruction 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 Treatment Best managed symptomatically. Artificial saliva and artificial tears. Good oral hygiene DD (Bilateral parotid swelling ) 1.Bacterial parotitis 2.Mumps 3. Sialosis(metabolic) 4. Sarcoidosis 5.Warthin’stumor 6. Benign lymphoepithelial lesions (Mikulicz’s disease)  Xerostomia (dry mouth) Causes of Xerostomia 1-Developmental (Salivary gland aplasia or atresia) 2-Loss of body fluids as: Impaired fluid intake Hemorrhage Vomiting and diarrhea 3-Medications as antihistamines, antidepressants, diuretic, Atropine, Decongestants, Bronchodilators and appetite suppressants. 4-Radiation therapy to the head and neck. 5-Systemic diseases as Sjogren’s syndrome, diabetes, HIV infection, anemia and Vitamin A deficiency. 6-Local Factors as smoking and mouth breathing. Ptyalism (sialorrhea) Excessive salivary secretion may be due to: Local reflexes (result from local irritation)such as: Oral infections (e.g. acute ulcerative gingivitis) Oral wounds Dental procedures New dentures NB: False ptyalism: Bell’s palsy, Parkinson’s disease (faulty neuromuscular control).