Untitled Quiz

Oral Cavity and Salivary Glands Pathology

• Caries (Tooth Decay): Caused by focal demineralization of enamel and dentin, resulting from acidic byproducts of bacterial sugar fermentation.

• Gingivitis: Inflammation of the oral mucosa surrounding teeth, caused by accumulation of dental plaque and calculus. Plaque is a mixture of bacteria, salivary proteins, and epithelial cells. If plaque isn't removed, it can harden into calculus.

• Periodontitis: An inflammatory process affecting the supporting structures of teeth (periodontal ligaments, alveolar bones, and cementum). This leads to loosening and eventual tooth loss.

Inflammatory Lesions

• Aphthous Ulcers: Common, recurring, painful ulcers. The cause is unknown but some possible triggers include the immune system becoming disturbed by external factors and reacting abnormally against a protein in mucosal tissue, along with emotional stress, lack of sleep, mechanical trauma, nutritional deficiencies (vitamin B, iron, folic acid), certain foods (chocolate), certain toothpastes, menstruation, medications (nicorandil), and viral infections. Initially, these are mononuclear but upon secondary bacterial infection become rich in neutrophils.

• Mucosal Ulceration: The inflammatory process in aphthous ulcers begins with mucosal ulceration.

• Submucosal Inflammation: Submucosal inflammation begins as mononuclear, but evolves into a neutrophil-rich response if secondary bacterial infection ensues.

Reactive/Fibrous Proliferative Lesions

• Irritation Fibroma (Traumatic Fibroma): A submucosal nodular mass of fibrous connective tissue stroma, primarily found on the buccal mucosa. Surgical excision is usually sufficient. It's thought to be a reactive process caused by repetitive trauma.

Infections

• HSV Infection (Oral Herpes): Commonly presents as gingivostomatitis in children, pharyngitis in adults. HSV infection also causes chronic mucocutaneous infection in immunocompromised individuals. The infection is caused by herpes simplex virus type 1 (HSV-1) and often characterized by vesicles and ulcers. It is a common oral infection that follows a latent stage within neural ganglia and will continue to recur.

• Oral Candidiasis: Caused by Candida albicans, a component of the oral flora in approximately 50% of the population. Some strains of Candida albicans, oral microbiome composition and immune status influence the severity of candidiasis.

Oral Manifestations of Systemic Disease

• Hairy Leukoplakia: A lesion on the lateral border of the tongue, often caused by the Epstein-Barr virus (EBV). It is a common problem in immune-compromised populations, such as those infected with HIV.

Oral Epithelial Dysplasia (OED)

• Oral epithelial dysplasia is divided into three grades of severity. It is considered a precancerous lesion.

Squamous Cell Carcinoma (SCC)

• Head and neck SCC is among the six most common cancers worldwide. Pathogenesis is complex, involving multiple factors. A key risk factor is tobacco and alcohol use in middle-aged adults. Pipe smoking and sunlight are risk factors for lower lip cancer. The incidence of oral cavity SCC in younger individuals is increasing, and second primary tumors occur frequently.

• 15% of premalignant lesions advance to SCC within five years. The cervical lymph nodes are common sites of metastases due to oral cavity carcinoma.

Xerostomia

• Xerostomia is a dry mouth condition, often caused by a decrease in saliva production. Older adults are more affected. Etiology includes autoimmune disorders such as Sjögren syndrome, and radiation therapy for head and neck cancers. Certain medications (anticholinergic, antidepressant/antipsychotic, diuretic, antihypertensive, sedative, muscle relaxant, analgesic, antihistamines) can also cause xerostomia as a side effect.

Sialadenitis

• Inflammation of the salivary glands, which can be caused by trauma, viral or bacterial infection or autoimmune disease. Mucocele is the most common non-neoplastic lesion of the salivary glands (usually due to trauma). Mumps is the most common viral sialadenitis.

Mucocele

• Most commonly found on the lip, a mucocele is a common non-neoplastic (not cancerous) lesion in the salivary glands. Trauma is the most frequent cause. They present as swelling often blue in color.

Ranula

• A mucocele specifically originating from the sublingual gland. Often a swelling under the tongue.

Sialolithiasis

• Obstruction of the salivary gland duct by stones (calculus). Commonly found in the submandibular gland. Characterized by concentric lamination of calcification surrounded by compressed epithelium.

Salivary Glands Neoplasms

• Over 30 different tumors are possible. 65-80% are found in the parotid gland. 40% of submandibular gland tumors are malignant. %50 of all minor salivary glands tumors are malignant, while 70-90% of sublingual gland tumors are malignant. The smaller the gland, the more likely it is to be malignant.

Benign Tumors

• Pleomorphic Adenoma (PA): The most common, slow growing, painless, mobile mass. 60% of all parotid gland tumors. It's a mixture of epithelial, myoepithelial, and mesenchymal cells. Histologically, it is characterized by heterogeneity and the presence of myxoid and hyaline tissue.

• Warthin Tumor (Papillary Cystadenoma Lymphomatosum): Commonly found in the parotid gland. It's almost exclusively located in the superficial lobe of the parotid gland. Second most common Salivary gland tumor. Benign. It's composed of epithelial and lymphoid cells, and commonly displays a high degree of heterogeneity.

• Other benign types: Oncocytoma, Canalicular adenoma, Basal cell adenoma, Ductal papillomas are covered in more detail and subcategorized descriptions.

Malignant Tumors

• *Carcinoma ex pleomorphic adenoma: Malignant transformation of a previously benign PA. The percent chance of this transformation increases with age, it being 2% for individuals under 5 years of age, and %10 for individuals older than 15 years of age, The cancerous cells show typical characteristics, such as a high degree of aggressiveness.

• Mucoepidermoid carcinoma (MEC): Most common malignant salivary tumor, often found in the parotid gland (60-70%). Show ill-defined, partially cystic areas on a cut surface, of varying histology ranging from low grade to high grade.

• Adenoid Cystic Carcinoma (AdCC): Commonly found in minor salivary glands, most often the palatine. Unpredictable, slow-growing, infiltrative tumors and are more likely to recur and metastasize to distant sites. Has a typical microscopic "eye of the storm" appearance with concentric rings and swirls around blood or nerve vessels.

• Acinic cell carcinoma (ACC): Mostly found in the parotid gland, it's characterized by a proliferation of acinar cells. It may be bilateral or multifocal. Often contains typical "purple granules", also known as zymogen granules.

• Polymorphous Adenocarcinoma (PAC): Second most common intraoral salivary gland carcinoma, frequently in the palate (60%). Presents as a slowly growing mass, and has varied cellular patterns. Recurrence rate is low after excision.

• Salivary Duct Carcinoma about 9% of malignant salivary gland tumors, often found in the superficial parotid gland, is typically aggressive and has a high rate of recurrence and metastasis.