Pseudoepithelial hyperplasia

PEH in oral cavity

1. Pseudoepitheliomatous hyperplasia (PEH) pseudocarniomatous hyperplasia verrucoid epidermal hyperplasia invasive epidermal hyperplasia

2. Definition abnormal reactive proliferation of the surface epithelium as irregular squamous strands extending down into the underlying connective tissue a histopathological reaction pattern epidermis of the skin epithelium of oral mucosa mimic a neoplastic growth

3. Reactive nature dermatological diseases; but gingiva , palate and tongue categorized as either: primary PEH (Primary gingival PEH) secondary (granular cell tumor or chronic irritation).

4. Histopathological appearance irregular or tongue-like proliferation of the squamous epithelium into the underlying connective tissue mimic squamous cell carcinoma a typia keratin pearls extensive acanthosis few mitotic figures inflammatory exudate glandular structures

5. Clinical appearance elevated nodule Verrucous growth or smooth/warty dome-shaped lesions raised margins of the chronic non-healing wounds rarely exceed beyond 1 cm exception of granular cell tumor present as several centimeter

6. The color of the lesion also depends on the nature of the underlying condition or inflammation and the depth of the lesion .

7. Mechanism of PEH Unknown Cytokines released from: the inflammatory process the underlying tumor cell mass Example: Chronic non-healing wound, ulcer, infection ( mycobacterial , fungal and parasitic), malignancy and retained foreign bodies

8. They are most commonly observed in case of chronic non-healing wound

9. Histogenesis of PEH effects of cytokines released by inflammatory cells or tumor cells epidermal growth factor (EGF), Transforming Growth Factor-α (TGF-α), Epidermal Growth Factor Receptor (EGFR), Fibroblast growth Factor (FGF) and Platelet Derived Growth Factor (PDGF)

10. PEH in fungal infection Systemic mycosis like paracoccidiomycosis chronic infection with a granulomatous histological picture These granulomatous reactions are associated with PEH like features

11. PEH in malignant melanoma very rare commonly seen in other benign pigmented lesions like Spitz nevi and intramucosal nevi .

12. Granular cell tumor benign neoplasm head and neck region tongue is the most common location histiocytes , fibroblasts, myoblasts , neural sheath cells, neuroendocrine cells, and undifferentiated mesenchymal cells growth factor on surface epithelium

13. Lichen planus Hyperplastic lichen planus are sometimes confused with PEH a slight chance of malignant transformation of lichen planus

14. Necrotizing sialometaplasia Benign appearing, self-healing lesion of salivary gland origin hard palate any area of oral cavity having salivary gland tissue due to trauma local anaesthesia , traumatic injury, previous surgery, ill-fitting dentures, and upper respiratory infections differentiated from squamous cell carcinoma and mucoepidermoid carcinoma

15. Pemphigus vegetans 1 to 2% of pemphigus gingiva with a purulent surface on a red base heal by formation of vegetation of hyperplastic granulation tissue PEH seen only in the advanced lesions

16. Wegener’s granulomatosis uncommon disease of unknown cause granulomatous lesion involving the respiratory tract, necrotizing glomerulonephritis and systemic vasculitis involving small arteries and veins strawberry gingivitis

17. Miscellaneous lesions Median rhomboid glossitis , chronic hyperplastic candidiasis Epulis fissuratum TUGSE (Traumatic Ulcerative Granuloma with Stromal Eosinophilia ) Oral submucous fibrosis

18. Median rhomboid glossitis depapillated zone in central aspect of dorsum of tongue just anterior to circumvallate papilla . candidal infection Other fungal lesion which may show features of PEH is chronic hyperplastic candidiasis

19. Epulis fissuratum flange region of the ill-fitting denture overlying epithelium exhibits hyperparakeratosis or in some circumstances manifest as PEH

20. TUGSE (Traumatic Ulcerative Granuloma with Stromal Eosinophilia ) A chronic, self-limiting reactive lesion most commonly seen in the tongue exaggerated response to trauma erythema , surrounding an ulcer covered by fibrinopurulent membrane, with rolled out borders . inflammatory mediators, resulting in chronic inflammatory response as well as tissue destruction borders of the lesions