Pathology of Oral Mucosa and Salivary Glands PDF

Pathology of oral mucosa and salivary glands  Oral mucosa diseases (OMD) These include: Aphthous stomatitis. Herpes infection. Oral candidiasis. Leukoplakia. Glossitis Oral carcinoma.  OCD Aphthous stomatitis (ulcerative stomatitis): – Common s...

Pathology of oral mucosa and salivary glands  Oral mucosa diseases (OMD) These include: Aphthous stomatitis. Herpes infection. Oral candidiasis. Leukoplakia. Glossitis Oral carcinoma.  OCD Aphthous stomatitis (ulcerative stomatitis): – Common small, painful sore/s (ulcer/s) inside the mouth that typically begin in childhood and recur frequently. – Cause: unknown. – Predisposing factors: stress, fever, and certain foods. – Gross: Small (less than 1 cm), painful, shallow ulcers. Sites: oral mucosa and tongue. – Fate: resolve within 7-14 days without Aphthous stomatitis, gross Two ulcers are found on the mucous membrane of lower lip.  OMD Herpes infections: – Caused by HSV-1, rarely by HSV-2. – May cause acute herpetic gingivo- stomatitis in children. – Gross: vesicles containing clear fluid, usually on lips and oral mucosa. – Microscopic: cellular edema, intra- nuclear inclusion bodies, & giant cells. – Fate: the vesicles heal within 3-4 weeks. Herpes stomatitis, gross Multiple vesicles on the upper and lower lips and around the corner of the mouth. Ulcers in oral mucosa.  OMD Oral Candidiasis (moniliasis, thrush): – Common fungal infection in infants and persons with impaired immunity, diabetes, and cases of neutropenia. – Caused by Candida Albicans : normal inhabitant of the oral cavity (in 30-40% of population). – Gross: whitish areas on an inflammatory mucosa. Candida stomatitis, gross Tongue of an infant showing whitish areas due to infection by Candida albicans.  OMD Leukoplakia: – white plaque on the oral mucosa or the tongue due to epithelial thickening. – Causes: heavy smoking, chronic friction of a ragged tooth, and alcohol abuse. – Malignant change occurs in 3-6% of cases. – Microscopic: Acanthosis (increase thickness of prickle cells). Hyperkeratosis (hypertrophy of the horny layer). With or without dysplastic changes. Leukoplakia, tongue Gross: white patches on the right side of the tongue. Microscopic: – Acanthosis. – Hyperkeratosis. Glossitis is an inflammation of the tongue. The condition may present clinically as a painful tongue, as a change in the surface appearance of the tongue like changes in texture (Atrophy of papillae) or changes of color (Beefy-red) or both. There are numerous potential etiologies for glossitis. These include: 1-Anemia: Iron-deficiency anemia or Pernicious anemia 2-Vitamin B deficiencies: 3- infections 4- Medications e.g. sulphanilamide, sulphathiazole, ACE (Angiotensin-converting enzyme) inhibitors and Albuterol  OMD Oral carcinoma (squamous cell carcinoma): – Constitutes 95% of oral cancers. – Occurs between ages 50 & 70. – Causes: Tobacco smoking (the most common). Alcohol abuse. Leukoplakia. Human papilloma virus (HPV) infection. Chronic irritation (e.g. by a ragged tooth).  OMD Gross appearance: – Ulcerative or verrucous lesions (exophytic/raised growth). – Sites: floor of the mouth (common), tongue & soft palate. Microscopic: – Typical squamous cell carcinoma of variable differentiation. Oral carcinoma, microscopic Malignant squamous cells. Well differentiated (formation of cell nests)  Salivary gland diseases (SGD) These include: Oral mucoceles. Acute sialadenitis. Chronic sialadenitis. Tumors.  SGD Oral mucoceles: – Most common salivary gland lesions. – Due to ductal blockage by trauma or inflammation. – Usually affect small glands on the lower lip. – Gross: Cyst filled with mucus. Variable in size. Oral mucocele  SGD Acute sialadenitis: – Inflammation of the major salivary glands may be of viral, bacterial or autoimmune origin. The commonest viral infection is mumps which usually causes enlargement of the parotid glands. There is diffuse interstitial inflammation marked by edema and mononuclear cell infiltration. Bacterial sialadenitis occurs secondary to ductal obstruction by stone (sialolithiasis) or by retrograde invasion by bacteria.  SGD Chronic sialadenitis: – Occurs due to decreased secretion of saliva and subsequent inflammation. – The commonest cause is autoimmune sialadenitis (e.g. Sjögren syndrome), which characterized by: Dry eyes (kerato-conjuctivitis sicca) Dry mouth (xerostomia). – There is diffuse inflammation and focal lymphocytic aggregates. Focal lymphocytic aggregates in salivary gland  SGD Salivary gland tumors: Incidence: – 65-80% of tumors occur within the parotid glands (15-30% are malignant ). – 10% occur in submandibular glands (30- 40% are malignant). – 10% in minor salivary glands.  SGD Classification of salivary gland tumors: Benign Malignant Pleomorphic adenoma (benign Mucoepidermoid carcinoma mixed tumor) (50%) (15%) Warthin tumor (5-10%) Adenocarcinoma (10%) Oncocytoma (1%) Acinic cell carcinoma (5%) Other adenomas (basal cell Adenoid cystic carcinoma (5%) adenoma and canalicular adenoma) 5-10% Ductal papillomas Malignant mixed tumor (3-5%) Squamous cell carcinoma (1%) Other carcinomas (2%)  SGD Benign tumors: Pleomorphic adenoma (benign mixed salivary tumor): Slowly growing painless swelling. Site: parotid gland at the angle of the jaw. Gross: – Well demarcated mass. – Encapsulated. – Rarely exceeds 6 cm in greatest Pleomorphic adenoma Left parotid region Swelling at the angle of right lower jaw.  SGD Microscopic: – Epithelial structures forming ducts, acini, tubules, & sheets of cells. – Loose myxoid connective tissue stroma containing islands of apparent chondroid or bone tissue. Malignant transformation may occur in 10% of cases. Pleomorphic adenoma, microscopic Epithelial structures (yellow arrow). Loose myxoid structures (red arrow)  SGD Warthin tumor (papillary cystadenoma lymphomatosum): Less common than pleomorphic adenoma. Most common in smokers. Gross: – Typically found in parotid gland. – Usually small and well capsulated. – 10% are bilateral. Warthin tumor, microscopic Cystic spaces. Lined by two layers of cells. Well developed lymphoid tissue.  SGD Malignant tumors: Mucoepidermoid carcinoma: The most common salivary carcinoma (15%). Gross: – Measures up to 8 cm in diameter. – Lacks well defined capsule.  SGD Microscopic: – Cords or sheets of malignant squamous cells. – Mucous cells filled with mucin. Prognosis: – High grade tumors have 25% recurrence and 50% 5 year survival rates. Muco-epidermoid carcinoma, microscopic Sheets of malignant squamous cells. Mucous cells filled with mucin pushing the nuclei to the periphery.  SGD Adenoid cystic carcinoma: Relatively uncommon. Microscopic: – Small cells with scant cytoplasm. – The cells arranged in tubular or cribriform patterns. Prognosis: 5 year survival rate is about 60%. Adenoid cystic carcinoma, microscopic Small cells with scant cytoplasm. There is tubular and cribriform pattern.  SGD Acinic cell tumor: Constitutes about 3% of all salivary gland tumors. Occurs most commonly in parotid glands. 10-15% metastasize to the lymph nodes. Microscopic: the tumor cells resemble normal salivary serous acinar cells but it is malignant. Prognosis: 5 year survival rate is 90%. Acinic cell tumor, microscopic The tumor cells resemble normal salivary acinar cells