Oral Pathology — 30-Min Notes

1. White & Red Lesions

• Leukoplakia: Most common premalignant lesion of oral cavity. Defined as a white patch not scrapable and not attributable to any other disease. Tobacco is the most common etiological factor.

• Erythroplakia: Red velvety lesion with the highest malignant transformation rate. Most cases show severe dysplasia or carcinoma in situ histologically.

• Oral Lichen Planus: Chronic autoimmune mucocutaneous disorder. Wickham’s striae are seen in reticular type; erosive type carries malignant potential.

• Tip: Red lesions are more dangerous than white lesions in exams.

2. Oral Cancer

• Squamous Cell Carcinoma: Accounts for >90% of oral malignancies. Common sites are tongue and floor of mouth; tobacco and alcohol act synergistically.

• Verrucous Carcinoma: Low-grade variant of SCC with slow growth and pushing margins. Rarely metastasizes and has good prognosis.

• Early spread of oral cancer is via lymphatics to submandibular and cervical lymph nodes.

• Tip: Tongue cancer → lateral border most common site.

3. Odontogenic Tumors

• Ameloblastoma: Benign but locally aggressive tumor. Shows multilocular “soap bubble” or “honeycomb” radiolucency, commonly in posterior mandible.

• Odontoma: Most common odontogenic tumor; considered a hamartoma. Compound type resembles tooth-like structures, complex type appears as irregular mass.

• Odontogenic Myxoma: Locally aggressive tumor with tennis-racket trabeculation pattern.

4. Odontogenic Cysts

• Radicular Cyst: Most common odontogenic cyst. Arises from epithelial rests of Malassez due to pulpal infection of non-vital tooth.

• Dentigerous Cyst: Associated with crown of unerupted tooth, especially mandibular third molar. Fluid accumulates between reduced enamel epithelium and crown.

• OKC (Odontogenic Keratocyst): High recurrence rate due to daughter cysts; associated with Gorlin-Goltz syndrome.

• Tip: OKC shows parakeratinized epithelium.

5. Salivary Gland Lesions

• Mucocele: Most common salivary gland lesion. Occurs due to trauma to minor salivary glands, commonly on lower lip.

• Pleomorphic Adenoma: Most common benign salivary gland tumor. Commonly affects parotid gland and has mixed epithelial and mesenchymal components.

• Warthin Tumor: Second most common benign parotid tumor; associated with smoking.

6. Vesiculobullous Disorders

• Pemphigus Vulgaris: Autoimmune disorder with intraepithelial blister formation. Positive Nikolsky sign; antibodies against desmoglein.

• Pemphigoid: Subepithelial blistering disorder. Less severe oral involvement compared to pemphigus vulgaris.

• Recurrent Aphthous Ulcer: Painful ulcers affecting non-keratinized mucosa; minor type most common.

7. Bone Lesions

• Fibrous Dysplasia: Developmental disorder with replacement of normal bone by fibrous tissue. Radiograph shows ground-glass appearance.

• Osteomyelitis: Inflammation of bone and marrow due to infection. Mandible affected more commonly due to poor blood supply.

• Central Giant Cell Granuloma: Occurs commonly in anterior mandible and may cross midline.

8. Pigmented Lesions

• Melanotic Macule: Benign pigmented lesion caused by increased melanin deposition. Commonly seen on lips and gingiva.

• Oral Melanoma: Rare but highly aggressive malignancy. Common sites are palate and maxillary gingiva.

• Tip: Oral melanoma has very poor prognosis.

9. High-Yield Repeated Points (NEET MDS)

• Leukoplakia → most common premalignant lesion

• Erythroplakia → highest malignant potential

• SCC → most common oral cancer

• Ameloblastoma → soap-bubble radiolucency

• Radicular cyst → most common odontogenic cyst

• Mucocele → most common salivary gland lesion

• Pemphigus vulgaris → Nikolsky positive