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Pathology of GIT

BY AYAL M(MD)

Course content 2

Disease of oral cavity Disease of the esophagusDisease of the stomachPathology of small and large intestinePathologic disorders of liver and gallbladder

Disease of pancreas

Diseases of the Oral Cavity

Caries (Tooth Decay) Def. Focal degradation of the tooth structure Mineral dissolution of tooth structure by acid metabolic end products from bacteria that are present in the oral cavity capable of fermenting sugars

GingivitisDef. Inflammation of soft tissue that surround the teeth Most prevalent at adolescence: and result from lack of proper oral hygiene, leading to accumulation of dental plaque and calculus

Dental plaque - is a mass formed by microorganisms from the normal oral flora, proteins from saliva, and desquamated epithelial cells

Calculus – consists of mineralized bacterial plaque and can form extensive deposits around the teeth

SSx: features of chronic inflammation- gingival redness, edema, bleeding, changes in contour

Dental plaque/calculus5

PeriodontitisDef. An inflammatory process that affects the supporting structures of the teeth: periodontal ligaments, alveolar bone, and cementum=> Loosening and eventual loss of teeth are possible

Common cause of tooth lose in old age Causes Pockets along side of the tooth

Pathogenesis: A shift in the type and proportions of bacteria along the gums (more anaerobic)

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Inflammatory/Reactive lesions

Def. Lesions representing inflammation, induced by irritation

Reactive nodules of the oral cavity1. Fibroma

Occurs on the buccal mucosa along the bite line formed when chronic irritation results in

reactive connective tissue hyperplasia. They may occur on any oral mucosal surface,

particularly the palate, tongue, cheek, and lip

Fibromas are typically pale pink, smooth, firm, less than 1 cm in diameter, and have a sessile or pedunculated base

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2.Pyogenic granulomaUsually in the gingivaHighly vascular proliferation similar to

granulation tissueSSx: Polypoid, ulcerated and bright red

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3. Peripheral ossifying fibroma Occurs on the gingiva Pathogensis: maturation of long standing pyogenic granuloma (?)

4. Peripheral giant cell granuloma Protrudes from gingiva More bluish purple Fibroblastic proliferation with scattered foreign body type giant cells

5. Aphthous ulcers (Canker Sores) Shallow oral mucosal ulcer

single or multiple hyperemic ulcerations

Often painful and recurrent Causation is obscure

6. Glossitis Lesion associated with vitamin B and iron deficiency states

Beefy red tongue Glossitis may be associated with ill fitting dentures

aphthous ulcer14

Infections of oral cavityHerpes simplex virus infections

Caused by HSV-type I Primary infection in children Reactivation produces cold sores

Trauma, fever, allergies, UV, infection, immunosupression

Oral candidiasis (Oral Thrush) Superficial, curdy, gray white inflammatory membrane composed of matted fungal organisms enmeshed in a fibrinosuppurative exudate that can be scraped off

Associated with immunosuppression

Oral candidiasis16

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Oral manifestations of systemic diseases

Hairy leukoplakia restricted to patients with HIV White, confluent patches of hairy hyperkeratotic & acanthotic thickening

Piled up layers of keratotic squames basing on underlying mucosal lesion

Precancerous lesionsLeukoplakia and Erythroplakia

Leukoplakia Def. White patch or plaque that can not be scraped off and can not be characterized as any other disease

Until proved by histologic evaluation, all leukoplakias must be considered precancerous

Range from benign lesions to markedly dysplastic changes

Erythroplakia Red, possibly eroded area that usually remains level with or may be depressed in relation to the surrounding mucosa

Incur much higher risk (10x) of malignant transformation

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Leukoplakia

leukoplakia21

Hairy leukoplakia22

Tumors of oral cavity

Squamous cell carcinoma Most common tumor of Head and Neck area 95% of cancers of the oral cavity Predisposing factors- Tobacco, alcohol, sunlight, ill fitting dentures

Favored locations – lower lip, floor of the mouth, tongue, hard palate, base of the tongue

Diagnosed late and thus poor prognosis Metastasis: to cervical L. nodes

Tongue carcinoma24

Ulcerated ca.

Oral cavity Sq. Cell Ca.25

Other Tumors of oral & Oropharynx26

Lymphoma Diffuse Large B-cell Lymphoma (Old age & AIDS) MALToma

Melanoma=malignant cell, sarcoma, tumor)

Leukemic infiltrates

Contd…27

Odontogenic cysts and tumors Ameloblastoma

True neoplasm & arises from odontogenic epithelium

It is commonly cystic, slow growing, and locally destructive

Odontoma – Hamartomatous- extensive deposition of enamel and dentin

Radicular cyst – Cyst related to the tooth root, usually after inflammation

Keratocyst- Cyst of dental lamina origin, lined by stratified squames epithelium

Ameloblastoma28

Ameloblastoma29

Keratocyst30

Diseases of Salivary Glands

Inflammation (Sialadenitis) Traumatic , viral, bacterial, autoimmune origin

Mucoceles – most common cystic lesion of oral cavity, follows duct obstruction after inflammation

Mumps- most common viral sialadenitis Sjogren syndrome- an autoimmune disease

Sialolithiasis and non specific Sialadenitis

Most often bacterial & involves submandibular glands

Pathogenesis: dehydration with decreased secretory function & may predispose to infection Usually, secondary to ductal obstruction by stones

Unilateral involvement of single gland is the rule

SSx: painful enlargement and sometimes purulent ductal discharge

Chronic sialadenitis33

Neoplasms of salivarygland

Classification Benign Malignant

Pleomorphic adenoma Mucoepidermoid carcinoma Warthin’s tumor Adenocarcinoma Oncocytoma Acinic cell carcinoma

Basal cell adenoma Adenoid cystic carcinoma

Ductal papillomas Squamous cell carcinoma

Tumors usually occur in adults with slight female preponderance

85% are benign and mostly in parotid

Pleomorphic Adenoma (mixed tumors) Represent about 60% of tumors in the parotid Said to be of myoepithelial origin with both epithelial and mesenchymal differentiation

Radiation exposure increases the risk Painless, slow growing, mobile and discrete mass

Malignant transformation (2%) increases with duration

Warthin tumor (Papillary cystadenoma lymphomatosum) Second most common, commonly in old age Almost always arises in the parotid gland Spaces lined by a double layer of epithelial cells resting on a dense lymphoid stroma sometimes bearing germinal centers

Bilateral or multicenteric

pleomorphic adenoma

Pleomorphic adenoma37

Warthin’s T.38

Mucoepidermoid carcinomaComposed of mixtures of three cells: squamous cells, mucus secreting cells, and intermediate cells Occur mainly in the parotids 15% of all salivary gland tumors Most common form of primary malignant tumor of salivary glands

Cords, sheets, or cystic configurations of squamous, mucous, or intermediate cells

Low grade lesions tend to be composed of largely mucus secreting cells (cystic)

High grade tumors are composed largely of squamous cells with only a scattering mucus secreting cells (solid)

Mucoepidermoid carcinoma40

Mucoepidermoid carcinoma41

Adenoid cystic carcinoma most common neoplasm in the minor salivary glands

Composed of small cells, having dark, compact nuclei and scanty cytoplasm

The cells tend to be dispersed in tubular, solid, or cribriform patterns

The spaces between tumor cells are filled with a hyaline material

Most painful (perineural invsasion) salivary gland neoplasm

Acinic cell tumor Composed of cells resembling the normal serous cells of salivary glands

Most arise in the parotid Bilateral or multicenteric The cells have apparent cleared cytoplasm The cells are disposed in sheets or microcystic, glandular, follicular, or papillary patterns

Little anaplasia and few mitoses

Adenoid cytic carcinoma43

Acinic cell carcinoma44