BDS10012 Oral Hyperplasia Lecture Notes PDF

BDS10012 Oral Hyperplasia Aims: The aim of this lecture is to review the histopathological features of epithelial hyperplasia of the oral mucosa and genetically determined white patches of the oral mucosa. Objectives: On completion of this lecture, the student should be able to: Understand the hi...

BDS10012 Oral Hyperplasia Aims: The aim of this lecture is to review the histopathological features of epithelial hyperplasia of the oral mucosa and genetically determined white patches of the oral mucosa. Objectives: On completion of this lecture, the student should be able to: Understand the histopathology of epithelial hyperplasia Understand the histopathology and management of genetically determined white patches of the oral mucosa Hyperplastic (or reactive) lesions These are tumor-like hyperplasias which show an exuberant tissue repair response to a chronic low-grade irritation or injury, such as: Cheek biting Trauma [due to broken tooth, sharp clasp or wire] Calculus overhanging dental restorations extended flanges of denture or ill fitting denture The main differences between reactive and neoplastic lesions Hyperplastic (Reactive) Have definite etiologic factors as: trauma, inflammation, infection (viral) or excessive functional demand Neoplastic May occur spontaneously without definite cause [may be caused by Chemical carcinogens, Ionizing radiation & Certain viruses] There is a direct relation between the growth of the reactive or hyperplastic lesions and that of the stimulus. Autonomous Usually regress and undergo atrophy when the causative stimulus is removed. sustain their excessive abnormal growth and do not regress 1. Irritational fibroma (Fibroepithelial polyp or focal fibrous hyperplasia or fibrous nodule) Reactive hyperplastic lesion of fibrous tissue [Most common tumor in the oral cavity] Etiology Cheek biting sharp carious tooth sharp clasp or wire (not entire denture border). 1. Irritational fibroma Clinical features It can occur at any intraoral site Most common site buccal mucosa [along the bite line] & gingiva [epulis] Sessile or pedunculated mass with smooth surface The same colour of the mucosa or slightly paler. Soft or firm depending on fibrous content 1. Irritational fibroma Histopathology Hyperplastic stratified squamous epithelium Excessive bulk of connective tissue composed of fibroblasts, collagen fibers and blood vessels infiltrated with chronic inflammatory cells. 1. Irritational fibroma Bone formation is sometimes seen in a fibrous epulis, this combination is termed a peripheral ossifying fibroma 1. Irritational fibroma Leaf fibroma It usually occurs on the hard palate beneath a maxillary denture It appears clinically as a pink flattened pedanculated mass It is attached to the palate & is easily lifted up with a probe The edge of the lesion is serrated , it resembles a leaf Peripheral ossifying fibroma  is a relatively common gingival growth  It could be due to Bone formation in a fibrous epulis Or may develop initially as pyogenic granulomas that undergo fibrous maturation and subsequent calcification. Inflammatory fibrous hyperplasia due to ill fitting denture Leaf fibroma Epulis fissuratum Palatal papillomatosis 2.Epulis fissuratum (denture injury, denture fissuratum, denture epulis) Clinical features Hyperplastic tissue occurs along the denture border and is characterized by elongated rolls of tissue in the vestibule The flange of the denture fits in the fissure between folds 2.Epulis fissuratum (denture injury, denture fissuratum, denture epulis) Clinical features Hyperplastic tissue occurs along the denture border or on the gingiva and is characterized by elongated rolls of tissue in the mucolabial or mucobuccal folds. The flange of the denture fits in the fissure between folds 2.Epulis fissuratum Histopathology Hyperplastic stratified squamous epithelium Excessive bulk of connective tissue composed of fibroblasts, collagen fibers and blood vessels infiltrated with chronic inflammatory cells. Osteoid or chondroid tissues may be observed, known as Osseous & chondromatous metaplasia 3. Inflammatory papillary hyperplasia ( Palatal papillomatosis) Unusual condition involving the mucosa of the hard palate due to: ill fitting denture Poor denture hygiene Wearing the denture 24 hours  usually superimposed candidal infection by 3. Inflammatory papillary hyperplasia ( Palatal papillomatosis) Clinical features It appears as numerous closely arranged red edematous papillary projections on the hard palate, and onto alveolar mucosa. 3. Inflammatory papillary hyperplasia ( Palatal papillomatosis) Histopathology Numerous overgrowths formed of hyperplastic stratified squamous epithelium Central core of connective tissue showing dilated blood vessels and infiltrated with chronic inflammatory cells. 3. Inflammatory papillary hyperplasia ( Palatal papillomatosis) Treatment: Conservative treatment of denture hygiene, cessation of night wear and treatment of any superimposed candidal infection is usually sufficient. Surgical removal and denture remaking may be considered 4. Pyogenic granuloma Is a reactive hyperplastic lesion characterized by excessive formation of highly vascularised fibrous connective tissue , it is considered as vascular tumor Etiology Trauma Poor oral hygiene is a precipitating factor 4. Pyogenic granuloma Clinical features it occurs mainly on the gingiva, less commonly, may appear on the lip, tongue and buccal mucosa. It appears as an pedunculated or sessile painless soft mass It is deep red or reddish purple in color, depending on the vascularity of the lesion. 4. Pyogenic granuloma Histopathology It is formed of localized granulation tissue infiltrated with chronic inflammatory cells and showing numerous dilated blood vessels Covered by hyperplastic stratified squamous epithelium. 4. Pyogenic granuloma  Pyogenic granuloma if left untreated will attain more fibrous appearance and resembles irritational fibroma. Differential Diagnosis Clinically Pregnancy tumor. Peripheral giant cell granuloma Rarely, metastatic cancer Histologically Pregnancy tumor. Capillary hemangioma [PG contains inflammatory cells] Pregnancy tumor It is believed that pregnancy tumor is a pyogenic granuloma which was modified by the hormonal status of pregnancy. It usually occur as a reaction to mild trauma Treatment: Surgical excision after delivery of the baby. It may recur if excised in pregnancy 5. Peripheral giant cell granuloma (Giant cell epulis) A lesion which represents an unusual reaction of tissue against local irritation (mostly trauma, with poor oral hygiene)[it is characterized by proliferation of multinucleated giant cells] Clinically: - painless swelling, similar to pyogenic granuloma [but more bluish purple in color] - Sessile or pedunculated - Exclusively on gingiva or alveolar mucosa [usually anterior to molar area] - May show surface ulceration and bleeding 5. Peripheral giant cell granuloma (Giant cell epulis) Radiographic features May show superficial erosion of underlying bone (cupping or saucerization) 5. Peripheral giant cell granuloma (Giant cell epulis) Histopathology  Hyperplastic epithelium  Subepithelial zone, free of giant cells  Mass of connective tissue (collagen fibers, fibroblasts, blood capillaries)  Multinucleated giant cells 6.Traumatic neuroma (amputation neuroma) Is a hyperplastic lesion of neural tissue It occurs following damage or cut to a nerve, trunk as a result of accidental or purposeful sectioning of a nerve (as in excision of a tumor nearby or may be incidental to difficult extraction). 6.Traumatic neuroma (amputation neuroma) Repair of damaged nerve begins with proliferation of axons through tubes of proliferating Schwan cells When the proliferating proximal end meets its distal part, repair and re-innervation usually occur. But if the proliferating proximal end meets some obstruction as scar tissue or mal-alignment, the neural tissue continues to proliferate in an unorganized manner forming a nodular mass 6. Traumatic neuroma (amputation neuroma) Clinical features It mainly occurs at mental foramen area and may occur in other sites as lip and tongue The lesion is most commonly painful 6.Traumatic neuroma (amputation neuroma) Histopathology It is composed of a haphazard proliferation of nerve bundles within a fibrous connective tissue infiltrated with chronic inflammatory cells. Papillomas These lesions have spiky exophytic or cauliflower-like shapes, probably all are caused by human papillomavirus (HPV) even though it cannot be detected in some lesions. Oral papillomas are occasionally multiple but,if numerous, HIV infection or other cause of immunodeficiency should be suspected. 1. Squamous cell papilloma 2. Verruca vulgaris 3. Focal epithelial hyperplasia (Heck’s disease) 4. Condyloma accuminatum 5. Verruciform xanthoma 7. Squamous cell papilloma It is a hyperplastic exophytic localized proliferation with a verrocous or cauliflower like morphology Etiology: The lesion is induced by human papilloma virus (HPV 6, 11) 7. Squamous cell papilloma Clinical features  Exophytic growth formed of numerous finger like projections giving the lesion rough verrucous surface or cauliflower like appearance  Painless, commonly pedunculated and some times sessile  Any oral site may be affected, most commonly soft palate, tongue or lip  May be pink (nonkeratinized) or white (keratinized) 7.Squamous cell papilloma Histopathology 7.Squamous cell papilloma Histopathology Multiple thin long finger like projections made up of Epithelium 1. Hyperplastic 2. Show hyperkeratosis or non keratinized Connective tissue 1. Thin branched core that contains blood vessels 2. Infiltrated with chronic inflammatory cells 8.Verruca vulgaris It is a hyperplastic warty lesion in response to viral infection The lesion is induced by human papilloma virus (HPV 2, 4) Clinical features It appears as an exophytic small mass pedunculated or sessile painless , of rough surface, white cauliflower like in appearance. It occurs intraorally only in case of autoinoculation (through thumb sucking or nail biting habits.) 8. Verruca vulgaris Histopathology Formed of numerous finger like projections of keratinized stratified squamous epithelium Prominent granular cell layer and koilocytes covering thin core of fibrous connective tissue. 8. Verruca vulgaris: Histopathology Koilocytes are virus altered epithelial clear cells with small dark pyknotic nuclei, they are sometimes seen high in prickle cell layer Treatment Conservative surgical excision Laser ablation 9. Condyloma accuminatum (Venereal wart) It is a virus induced proliferation of st.sq. epithelium which is frequently sexually transimitted Mainly affects genetalia, perianal region, mouth and larynx HPV ( 6, 11, 16, 18) 9.Condyloma accuminatum (Venereal wart) Clinical features Favored intraoral sites are labial mucosa and lingual frenum Sessile, pink exophytic mass with short blunted surface projection Histopathology Similar to verruca vulgaris but the papillary projections are more blunt and broader without keratinization 10. Multifocal epithelial hyperplasia (Heck’s disease) It is HPV virus (13, 32) induced multifocal epithelial hyperplasia Low socioeconomic status and malnutrition may be contributing factors [seen in developing countries] Clinical features Multiple non tender, flattened papules similar in colour to normal mucosa These papules may coalesce forming plaques 10. Multifocal epithelial hyperplasia (Heck’s disease) Histopathology Hyperplastic keratinized epithelium Koilocytes present superficially in the spinous cell layer Mitosoid cell: a cell with altered nucleus that resembles the mitotic figure Mitosoid cell White spongy nevus  A hereditary condition (autosomal dominant)  It is due to abnormal keratinization of oral mucosa due to defects in keratin 4 or keratin 13 genes  It appears at birth or in early childhood & persists for life White spongy nevus Clinical appearance Characterized by greyish white spongy areas of the oral mucosa with fissures and folds Most commonly affect buccal mucosa, floor of mouth & ventral surface of tongue spongy and soft upon palpation. It often exhibits a symmetric wavy pattern White spongy nevus Histopathology It usually shows an intact basal layer with acanthosis There is hyperkeratosis and parakeratosis Mild chronic inflammatory cell infiltrate Intercellular & intracellular oedema or vacuolation of the prickle cell layer giving rise to the so called basket-weave appearance Genodermatosis are genetic diseases with cutaneous expression. They are various (around 400) and almost all rare. Dyskeratosis Congenita, is a rare disease with several inheritance patterns caused by loss of chromosomal telomeres. The main oral feature is dysplastic white or red lesions , cutaneous pigmentation, dystrophies of the nails and haematological abnormalities Pachyonychia Congenita Pachyonychia congenita is a rare genetic disorder characterized mainly by hypertrophy of the nails and hyperkeratosis of the skin and mucosae. Key points Hyperplastic epithelium & connective tissue Irritational fibroma Oral Hyperplasia Hyperplastic epithelium & connective tissue with special findings Pyogenic granuloma & pregnancy tumor [numerous dilated blood vessels] Hyperplastic epithelium Papillomas [reactive HPV induced] Denture fissuratum Palatal papillomatosis Hyperplastic neural tissue Traumatic neuroma Peripheral giant cell granuloma [numerous giant cells] White spongy nevus [genetic] Aims: The aim of this lecture is to review the histopathological features of epithelial hyperplasia of the oral mucosa and genetically determined white patches of the oral mucosa. Objectives: On completion of this lecture, the student should be able to: Understand the histopathology of epithelial hyperplasia Understand the histopathology and management of genetically determined white patches of the oral mucosa Reading material: Students are advised to review any relevant teaching provided in the first year. In addition they are advised to read relevant sections of the following texts: Robinson M et al. Soames’ and Southam’s Oral Pathology. 5th edition. Oxford University Press, 2018 pp 51-53 Odell E.W. Cawson’s Essentials of Oral Pathology and Oral Medicine. 9th Edition. Elsevier, 2017 pp 291-293 Gandolfo S, Scully c, Carrozzo M. Oral Medicine, Churchill Livingston, 2006 pp 56, 79 Felix D, Luker j, Scully C. Oral Medicine: Update for the Dental Team, Dental Update Books 2015 pp 45-46 Thank you