Head and neck pathology

Oral Pre-Malignant/Malignant - Risky Business

• Leukoplakia: White patch/plaque that cannot be scraped off. Represents epithelial hyperplasia/hyperkeratosis. Biopsy is crucial to rule out dysplasia or carcinoma.
• Erythroplakia: Red, velvety patch. Much higher risk of malignancy than leukoplakia; often represents severe dysplasia or carcinoma in situ.
• Squamous Cell Carcinoma (SCC): Most common oral malignancy (>90%).
  • Risk Factors: Tobacco, alcohol (synergistic effect), HPV-16 (esp. oropharyngeal), betel nut chewing, chronic irritation.

⭐ The floor of the mouth is a high-risk site for malignant transformation of leukoplakia.

Salivary Gland Tumors - Glandular Goons

• General Rules: Most tumors in parotid (~80%), most parotid tumors benign. As gland size ↓ (submandibular, sublingual), malignancy risk ↑.
• Benign Tumors:
  • Pleomorphic Adenoma (Mixed Tumor): Most common overall.
    • Painless, mobile mass with chondromyxoid stroma & epithelium.
    • High recurrence with incomplete excision.
  • Warthin Tumor: Almost exclusive to parotid; strong link to smoking.
• Malignant Tumors:
  • Mucoepidermoid Carcinoma: Most common malignant tumor.
  • Adenoid Cystic Carcinoma: Cribriform ("Swiss cheese") pattern; perineural invasion causes pain.

⭐ Facial nerve (CN VII) palsy is a significant red flag, strongly suggesting a malignant parotid tumor due to nerve invasion.

Nasopharynx & Larynx - Airway Afflictions

• Nasopharyngeal Carcinoma: Strongly linked to EBV; common in Southern China/Africa. Presents with nasal obstruction, epistaxis, or a metastatic neck mass.
• Laryngeal Papilloma: Benign tumor of vocal cords caused by HPV 6 and 11.
  • Single in adults, multiple (recurrent respiratory papillomatosis) in children. Presents with hoarseness.
• Laryngeal Carcinoma (SCC): Key risk factors are smoking and alcohol.
  • Persistent hoarseness is a cardinal sign. Other symptoms include dysphagia and cough.

⭐ Undifferentiated nasopharyngeal carcinoma has the strongest association with EBV and often presents with a neck mass from nodal metastasis.

Odontogenic Lesions - Jaw-Dropping Growths

• Ameloblastoma: Benign but locally aggressive. Presents as a "soap bubble" or honeycomb multilocular radiolucency in the posterior mandible. High rate of recurrence if not completely excised.
• Keratocystic Odontogenic Tumor (KCOT): Aggressive cystic lesion known for high recurrence. Often seen in the posterior mandible. Multiple KCOTs are a key feature of Gorlin Syndrome (NBCCS).
• Odontoma: Most common odontogenic tumor; considered a hamartoma.
  • Compound: Multiple small, tooth-like structures (denticles).
  • Complex: Disorganized mass of dental tissue.

⭐ High-Yield: Ameloblastomas frequently harbor activating mutations in the BRAF V600E gene, a potential target for therapy.

High‑Yield Points - ⚡ Biggest Takeaways

• HPV-16 is a major driver of oropharyngeal SCC, especially in non-smokers, conferring a better prognosis.
• Nasopharyngeal carcinoma, particularly the undifferentiated type, is strongly associated with EBV infection.
• Pleomorphic adenoma is the most common benign tumor of the salivary glands, typically in the parotid.
• Mucoepidermoid carcinoma is the most common malignant salivary gland tumor.
• Branchial cleft cysts present as lateral neck masses, while thyroglossal duct cysts are midline.