Oral Cavity and Salivary Gland Pathology PDF

Pathology of Oral Cavity and Salivary Glands Dr. Leyla Cinel  Caries (tooth decay) It is caused by focal demineralization of tooth structure (enamel and dentin) by acidic products of bacterial sugar fermentation.  Gingivitis is inflammation of the oral...

Pathology of Oral Cavity and Salivary Glands Dr. Leyla Cinel  Caries (tooth decay) It is caused by focal demineralization of tooth structure (enamel and dentin) by acidic products of bacterial sugar fermentation.  Gingivitis is inflammation of the oral mucosa surrounding the teeth. It is caused by accumulation of dental plaque and calculus. Dental plaque contains a mixture of bacteria, salivary proteins and epithelial cells. They can become calculus if not removed.  Periodontitis An inflammatory process that affects the supporting structures of the teeth (periodontal ligaments), alveolar bones and cementum. This leads to loosening and eventually tooth loss.  Inflammatory lesions Aphthous Ulcers: common, recurrent, painfull. The cause is not known First 2 decades of life May be associated with immunological disorders including celiac disease, inflammatory bowel disease, Behçet Disease  Aphthous Ulcers Factors that seem to trigger outbreaks of Current thinking is that ulcers include: the immune system is Emotional stress and lack of sleep disturbed by some Mechanical trauma, for example, self-inflicted bite external factor and Nutritional deficiency, particularly of vitamin B, reacts abnormally iron, and folic acid against Certain foods, including chocolate a protein in mucosal tiss Certain toothpastes; this may relate to sodium laureth sulphate (the foaming component of ue toothpaste) Menstruation Certain medications, including nicorandil, given for angina Viral infections.  Aphthous Ulcers Mucosal ulceration Submucosal inflammation is initially mononuclear but becomes neutrophil rich upon secondary bacterial infection  Reactive/fibrous proliferative lesions Irritation fibroma: (travmatic fibroma) Submucosal nodular mass of fibrous connective tissue stroma Common on the buccal mucosa Surgical excision  Irritation Fibroma It is thought to be a reactive process induced by a repetitive trauma  Pyojenic granuloma: typically found on the gingiva Red color, ulcerated, exophytic inflamatory lesion Sometimes rapidly growing lesion makes malignity  Pyogenic granuloma Sometimes rapidly growing lesion makes malignity suspicion Histologically, pyogenic granulomas are a highly vascularized proliferation of organizing granulation tissue. Surgical excision  Infections HSV infection: Oral herpes usually presents as a gingivostomatitis in children, pharyngitis in adults, and chronic mucocutaneous infection in immunocompromised individuals Most orofacial Herpetic infection are caused by HSV-1 Vesicules and ulcers can occur HSV becomes latent/dormant within local neural ganglion  Oral candidiasis: Candida albicans is a component of oral flora in 50% of the population Some strain of candida albicans, oral microbiome composition and immune status are  Oral manifestations of systemic disease Oral lesions are often the first sign of underlying systemic conditions!!! Hairy leukoplakia: Lesion on the lateral border of the tongue caused by EBV Hairy hyperkeratotic thickening Usually occur in immunocompromised patients. May portend AIDS Unlike candidiasis, lesions can not be scraped off. Oral manifestations of some systemic disease Precancerous and cancerous lesions Leukoplakia: a white patch or plaque Can not scraped off This clinical term is reserved form lesions that are present in the oral cavity for no apparent reason. %5-25 of these lesions are premalignant.  Erythroplakia is a red lesion and malign transformation risk is much higher than leukoplakia Both of them is usually found in adults 2-1 male predominans Tobacco use is common risk factor  Histologic findings are variable in leukoplakia: Normal epithelium or dysplasia or carcinoma in situ But in erythroplakia, severe dysplasia, carcinoma in situ or minimally invasive carcinoma are seen %90 of cases.  Oral epithelial dysplasia OED is divided into three grades of severity Precancerous lesions  Squamous cell carcinoma (SCC) Head and neck SCC is the sixth most common carcinoma in the world. The pathogenesis of SCC is multifactorial. Within North America and Europe, oral cavity SCC is common in smoked tobacco and alcohol user middle-age adults. Pipe smoking and sunlight are known predisposing factors for lower lip cancer.  The incidence of oral cavity SCC in younger than 40 yrs, who have no known risk factors, has been on the rise. Second primary tumors occur at 3-7 % per year, the highest rate of among all malignancies. This concept is «field cancerization». The second primary tumors are commonly fatal. So early detection of premalign lesions is  In general, about 15% of premalignant lesions will progress to SCC within 5 years The cervical lymph nodes are favored sites of local metastasis  PATHOLOGY OF SALIVARY GLANDS Major salivary glands  Minor salivary glands There are innumerable minor salivary glands in the mucosa of oral cavity  Xerostomia Xerostomia is defined as a dry mouth resulting from a decrease in the production of saliva. Older than 70 yrs: Incidence is 20% Etiology: -Sjögren syndrome (autoimmune disorder) -Radiation therapy for head and neck cancers. -Drugs: a side-effect of anticholinergic, antidepressant/antipsychotic, diuretic, antihypertensive, sedative, muscle relaxant, analgesic and antihistamine drugs  Xerostomia may present as dry mucosa and/or atrophy of the papillae of the tongue, with fissuring and ulcerations In Sjögren syndrome, inflammatory enlargement of the salivary glands may also occur. Complications of xerostomia include increased rates of dental caries, candidiasis, and difficulty in swallowing and speaking  SIALADENITIS Sialadenitis is inflammation of the salivary glands. May be induced: trauma, viral or bacterial infection, or autoimmune disease Mucocele: The most common nonneoplastic lesion of salivary glands. Mumps: The most common viral sialadenitis, affect the major salivary glands especially parotis  Mucocele Mostly on the lower lip Trauma is the common cause All age Present blue color swelling  There is a blockage of a salivary gland duct that allow saliva leakage into the surrounding connective tissue. Histologically, mucoceles are pseudocysts lined by inflammatory granulation or fibrous connective tissue with  Complete excision of the cyst with minor salivary gland is required conversely they can recur.  Ranula Ranula is a mucocele that is of major salivary gland origin like the sublingual gland. «Rana» in Latin means frog  Sialolithiasis and Nonspecific Sialadenitis Nonspecific bacterial sialadenitis is common and most often caused by infection with Staf. Aureus and strept. Viridans. Following ductal obstruction by stones (Sialolithiasis) No underlying cause is detected in many sialolithiasis  Calculi are common in the submandibular gland Histologically, concentric lamination of calcification surrounded by compressed epithelium is seen.  Neoplasms More than 30 different tumors But only few tumors make up more than 90% of salivary gland tumors (SGT) SGT represents less than 2% of human tumors. Locations: %65-80 in parotid %10 in submandibular The remainder in minor glands and sublingual gland  Minority parotid tumors are malignant %40 of submandibular %50 of minor SG %70-90 of sublingual tumors are malignant So; the smaller glands the more malignant !!!  SGTs occur mostly in adults Slight female predominance but, Warthin Ts are more common in males Whatever tumor type, parotis gland tumors produce swelling in front of and below the ear SGTs are usually 4-6 cm in diameter and mobile on palpation Benign tumors are growing slow and present for many years  Pleomorphic Adenoma (PA) Most common SG neoplasm 60% of parotid tumors Relatively rare in minor SG Painless, slow-growing mobile, discrete masses Recurrent rate is about 4% after parotidectomy  PA consist of a mixture of ductal (epithelial), myoepithelial and mesenchymal cells: also called as Mixed tumors! PA mostly present rounded, well demarcated tumors Usually encapsulated  The dominant histologic feature is heterogeneity The epithelial elements resembling ductal cells The myoepithelial cells make tubules, strands or sheets. Backround is loose myxoid and hyaline tissue (mesenchymal)  Island of cartilage and rarely bone foci can seen Usually, no epithelial dysplasia or mitotic activity. The treatment is excision.  Histogenesis is uncertain. Radiation increases risk of PA developing PLAG1 overexpression and HMGA2 gene mutations are molecular findings of many cases.  Carcinoma ex pleomorphic adenoma Malignant transformation can be seen and its rates correlate with age of the lesion. Less than 5 years: Rate is 2% More than 15 years: Rate is 10% Cancers are usually adenocarcinoma or undifferantiated carcinoma They are among the most aggressive tumors of all SGTs.  Round, oval encapsulated masses 2-5 cm in diameter, Usually palpable lesions  In cut surface, narrow cystic or cleftlike spaces with polypoid projections of lymphoepithelial elements are seen  Tumors compose of epithelial and lymphoid cells. Lymphoid follicules can be seen  The epithelium consists of double layer oncocytic epithelial cells on a lymphoid stroma The term oncocyte (swollen cell in Greek) refers to large cells containing numerous mitochondria  Histogenesis of WT is debated. The epithelium is neoplastic or reactive??? But lymphoid cells are reactive Complete surgical excision is the first treatment choice. Mucoepidermoid carcinoma (MEC) Most common primary malignant tumor of salivary glands Representing 15% of all SGTs Most occur 60-70% in the parotid More common in women  Tumor can grow 8 cm in diamater They appear circumscribed  In cut surface, ill delinated, partially cystic apperance.  Histology demonstrates cords, sheets or cystic configurations of squamous, mucous or intermediate cells. MEC are subclassified as low, intermediate and high grade.  The prognosis is related to histological grade. Low grade MEC may invade locally and may recur in 15% of cases. But high grade MECs recur more and metastasize to distant sites in 30%. The treatment is surgical excision Radiation may be usefull if residual tumor is found at the surgical margins.  More than half of the cases are associated with a chromosomal translocation that creates a CRTC1-MAML2 fusion gene.  Adenoid Cystic Carcinoma (adCC) 50% of adCC occur in minor salivary glands especially palatine glands. Also occur in the nose, sinuses, upper airways, lung, breast and other sites. Pathogenesis is not defined, MYB-NFIB gene rearrangements are present in a subset of adCCs. Grossly, small, infiltrative tumors  Composed of small cells with dark compact nuclei and scant cytoplasm. Usually organized in a cribriform growth pattern that resemble Swiss cheese.  The spaces between the tumor cells are often filled with hyaline material thought to represent excess basement membrane  adCCs are unpredictable, slow growing tumors that tend to invade perineural spaces Regularly recur 50% or more eventually make distant metastasis Arising in minor SGs are poorer prognosis than in the parotid.  Acinic Cell Carcinoma (ACC) Represent only 2-3% of SGTs. Usually develop in parotid glands Like Warthin T, ACC can be bilateral or multifocal. Composed of resemble serous acinar cells of the salivary glands  The cytoplasm typically contains purple granules (zymogen granules) Recurrence is uncommon after excision but 15% of ACC can metastasize to lymph nodes.  Polymorphous Adenocarcinoma PAC is the second most common intraoral salivary gland carcinoma. (%60 palate) It has morphological diversity and infiltrative growth pattern Typically present as a painless mass of variable duration (week to 40 years)  Ulceration and bleeding are uncommon Prognosis is usually excellent  Microscopically, «eye of the storm» apperance is typical feature: concentric targeting or whorling are seen around nerves or blood vessels  Salivary Duct Carcinoma About 9% of malignant salivary GT Male>female (8:1) One of the most common types of malignancy arising ex pleomorphic adenoma Rapidly growing mass If arising in a pleomorphic adenoma, there is a rapid  Microscopically, resembles ductal adenocarcinoma of breast It is the most agressive SGT Common lymph node and distant metastases