Ludwig's Angina - 10 Marks (MS ENT University Exam)

Definition

• Scott-Brown's Otorhinolaryngology HNS, p. 472
• K.J. Lee's Essential Otolaryngology, p. 713

Etiology / Predisposing Factors

• Odontogenic (dental) origin - most common cause, accounting for ~80% of cases; lower second and third molars (teeth 36, 37, 46, 47) most often implicated
• Periapical abscess, periodontal disease
• Oral trauma, tongue piercings, floor of mouth lacerations
• Immunocompromised states (diabetes mellitus, HIV, malnutrition) predispose
• May rarely arise from frenuloplasty or salivary gland infections

Microbiology (Causative Organisms)

• Streptococcus viridans (most common aerobe)
• Staphylococcus aureus
• Bacteroides spp., Peptostreptococcus (anaerobes)
• Gram-negative rods
• The combination of aerobic and anaerobic bacteria produces synergistic necrotizing infection

Pathogenesis

1. Dental/periapical infection seeds the submandibular space
2. Infection spreads through fascial planes (NOT via lymphatics) - this is a key distinguishing feature
3. Bilateral sublingual and submandibular spaces are involved, along with the submental space
4. The infection tracks deep to the mylohyoid muscle, causing edema of the floor of mouth
5. The tongue is displaced posteriorly and superiorly, threatening the airway
6. If untreated, cellulitis extends beneath deep fascial layers to involve the larynx and mediastinum
7. No pus formation initially (cellulitis, not abscess) - hence the woody, brawny induration without fluctuance

Clinical Features

• Severe dental or submandibular pain
• Trismus (difficulty opening mouth)
• Dysphagia, odynophagia
• Drooling (cannot swallow saliva)
• Dysarthria ("hot potato" voice)
• Stridor and dyspnea (airway compromise)
• Systemic: fever, chills, malaise

• Bilateral, brawny, woody induration of the floor of mouth and submandibular region
• Swelling extending from chin to hyoid bone
• Tongue elevated, protuberant, and immobile
• Patient prefers the erect/sitting position (tripod posturing)
• Putrid halitosis
• No fluctuance on palpation (unlike an abscess)

Diagnosis

• Clinical diagnosis primarily
• CT scan with IV contrast - investigation of choice; delineates extent, identifies abscess pockets vs cellulitis, evaluates airway and mediastinal involvement
• MRI: useful for soft tissue delineation
• Blood investigations: raised WBC, elevated CRP/ESR, blood cultures
• Pus culture and sensitivity (if available)

Complications

1. Airway obstruction - most feared, can be fatal
2. Spread to parapharyngeal, retropharyngeal, and danger spaces
3. Descending necrotizing mediastinitis - most serious complication (high mortality)
4. Aspiration pneumonia
5. Septicemia and septic shock
6. Jugular vein thrombosis (Lemierre syndrome)
7. Carotid artery erosion
8. Glottic edema

Management

1. Airway Management (FIRST PRIORITY)

• Awake fiberoptic nasotracheal intubation - method of choice in a cooperative patient
• Emergency tracheostomy - when airway is critically compromised or fiberoptic intubation not possible
• Avoid blind nasotracheal intubation or direct laryngoscopy (distorted anatomy, risk of precipitating complete obstruction)
• ICU monitoring mandatory

2. Antibiotics

• Started immediately, intravenously, broad-spectrum with anaerobic coverage
• Regimens:
  • Penicillin + Metronidazole (classic)
  • Ampicillin-Sulbactam or Piperacillin-Tazobactam
  • Clindamycin (penicillin allergy)
  • Add Metronidazole for enhanced anaerobic cover

3. Surgical Drainage

• No clinical improvement within 24-48 hours of antibiotics
• Evidence of abscess formation on CT
• Progressive worsening

• Submental (collar) incision under general anesthesia
• Bilateral submandibular and sublingual spaces are drained
• Mylohyoid muscle incised to decompress floor of mouth
• Corrugated or Penrose drains placed
• Wound lightly sutured

4. Dental Treatment

• Extraction of offending tooth once acute infection is controlled

5. Supportive Care

• Steroids (controversial - may reduce edema)
• IV fluids, nutrition support
• Hyperbaric oxygen (adjunct in severe/refractory cases)

Field Cancerization - 10 Marks (MS ENT University Exam)

Definition and Concept

Historical Background

• Slaughter et al. (1953): Examined tissue adjacent to oral SCC and found multiple premalignant foci in what appeared to be normal mucosa. They coined the term "field cancerization" to explain why:
  1. Oral cancers are often multicentric in origin
  2. Tumor recurrences occur at mucosal margins that appear histologically normal
  3. Second primary tumors (SPTs) develop at remote sites within the UADT

Pathogenesis / Molecular Basis

Model 1 - Classical (Polyclonal/Independent) Model

• Chronic carcinogen exposure causes widespread genetic damage across the entire mucosa
• Multiple independent clones undergo malignant transformation simultaneously or sequentially
• Results in multiple, genetically distinct primary tumors

Model 2 - Monoclonal/Clonal Spread Model (more supported by modern molecular evidence)

• A single transformed cell acquires a growth advantage via a key mutation
• This cell proliferates and migrates ("lateralization") across the mucosal surface, forming a genetically altered field
• Further mutations within cells of this field lead to transformation at geographically distinct but genetically related sites
• Bedi et al. and Califano et al. showed via X-chromosome inactivation and microsatellite analysis that multiple head and neck primary tumors often arise from a single clone
• Tissues adjacent to malignant and premalignant lesions share common genetic changes (e.g., loss of heterozygosity at 3p and 9p)

Molecular Alterations in the Field

• Loss of heterozygosity (LOH) at 3p, 9p (CDKN2A/p16), 17p (TP53) - early events
• TP53 mutations - most common molecular change
• Telomerase activation
• Epigenetic changes - hypermethylation of tumor suppressor genes
• Transcriptomic and proteomic reprogramming
• The Warburg effect (increased glucose uptake and lactate production) can be detected in cytologically normal bronchial epithelium of smokers - very early event in field carcinogenesis
• Microsatellite instability
• Cyclin D1 overexpression

Clinical Significance

1. Second Primary Tumors (SPTs)

• Annual risk of SPT after index H&N SCC = 1-7%
• Cumulative 5-year risk ≥ 20%
• Risk persists for at least 10 years
• Sites: head and neck (most common), esophagus, lung
• SPTs may be synchronous (within 6 months of index tumor) or metachronous (after 6 months)
• Patients with Stage I/II H&N SCC are statistically more likely to die from an SPT than from the index tumor

2. Surgical Margins

• "Clear" margins on histology may still harbor molecular alterations
• Explains why local recurrence occurs at negative margins
• Guides the need for wider resections

3. Panendoscopy

• Justifies triple endoscopy (laryngoscopy + esophagoscopy + bronchoscopy) to look for synchronous primaries at time of index tumor diagnosis

4. Long-term Surveillance

• Mandates lifelong follow-up of patients with any H&N SCC

Carcinogen Associations

• Tobacco (smoked and smokeless) - primary carcinogen; causes widespread UADT mucosal damage
• Alcohol - acts as a co-carcinogen; enhances mucosal permeability to carcinogens
• Betel nut - especially in South/Southeast Asian populations
• HPV (Human Papillomavirus) - can create field effects in oropharyngeal mucosa
• Ionizing radiation

Sites Affected (UADT Field)

• Oral cavity
• Oropharynx
• Larynx (especially supraglottis, glottis)
• Hypopharynx
• Esophagus (extension of field)
• Tracheobronchial tree (in smokers)
• Nasal cavity and nasopharynx (less commonly)

Field Cancerization and Chemoprevention

• Retinoids (isotretinoin, tretinoin) - can reverse oral leukoplakia; however, side effects limit widespread use
• COX-2 inhibitors (celecoxib) - under investigation
• Metformin - case series show stabilization of field cancerization in non-diabetic head and neck cancer patients; promising, clinical trials needed
• Photodynamic therapy (PDT) - role in widespread premalignant or superficial oral carcinoma; uses Photofrin activated by 620-nm light
• Beta-carotene + Vitamin E - RCT showed no protective effect in male smokers
• Tobacco cessation - single most effective intervention

Implications for Surveillance and Treatment

Key Examination Points to Remember

• Airway first - always
• Dental origin (~80%), spreads via fascial planes not lymphatics
• Woody, brawny, non-fluctuant induration
• Awake fiberoptic intubation preferred over tracheostomy where possible
• Polymicrobial: streptococci + anaerobes
• Most feared complication: descending necrotizing mediastinitis

• Slaughter et al., 1953 - original description
• Entire UADT at risk after chronic carcinogen exposure
• Two models: polyclonal vs monoclonal clonal spread
• Explains SPTs, margin recurrence, and multicentric disease
• Annual SPT risk 1-7%; cumulative 5-year risk ≥20%
• Basis for panendoscopy, lifelong surveillance, and chemoprevention research