The initial definition of leukoplakia by the World Health Organization (WHO) as a 'white mucosal lesion' was refined to indicate "a white patch or plaque that cannot be characterized clinically or pathologically as any other disease" - with the inherent acknowledgement that the lesion may represent a cancer or a precursor to development of a cancer.

Further refinement in the definition has led to the contemporary definition of leukoplakia as "white plaques of questionable risk having excluded (other) known disease or disorder that carry no increased risk for cancer"

Benign Leukoplakia	Pre-malignant Leukoplakia
Laryngeal white lesions that are not leukoplakia	Overview of squamous dysplasia
Squamous hyperplasia causing laryngeal leukoplakia	Mild squamous dysplasia causing laryngeal leukoplakia
Parakeratosis causing laryngeal leukoplakia	Moderate squamous dysplasia causing laryngeal leukoplakia
Hyperkeratosis causing laryngeal leukoplakia	Severe squamous dysplasia or Carcinoma in situ causing laryngeal leukoplakia
Infectious proliferations causing leukoplakia	Carcinoma-in-situ vs Severe Dysplasia
Candidiasis causing laryngeal leukoplakia	Invasive squamous cell carcinoma causing laryngeal leukoplakia
Blastomycosis causing laryngeal leukoplakia	Verrucous Squamous Carcinoma Causing Laryngeal Leukoplakia
Imaging	Laryngeal leukoplakia progression to invasive squamous cell carcinoma 2009 to 2013 with supracricoid laryngectomy
Narrow band imaging of vocal cord leukoplakia flexible transnasal videolaryngoscopy	Surgical Approach
Esophagoscopy with narrow band imaging (NBI) for Reflux Esophagitis	Endoscopic Resection of Vocal Cord (Fold) Leukoplakia "Floating the Lesion" (video)
	Laryngeal Leukoplakia Case Example Endoscopic Resection
	KTP Laser for the Larynx

Some reports use terms keratosis and leukoplakia interchangeably

Detection

1. Often asymptomatic - incidental (larynx inspected by anesthesia / GI / Rhinology)
2. Associations: Dysphonia (throat irritation / chronic cough rarely result from the leukoplakia)

Incidence/Prevalence

1. Autopsy study (37 years ago) – 19% of males with ‘laryngeal keratosis’ - 80% were smokers.
   1. Laryngeal keratosis seen in only 4.2% of nonsmokers (Muller 1980)
2. Medical record review 1935-84 Rochester Minnesota (Bouquot 1991)
   1. Annual incidence of detection:
      1. vocal fold keratosis in 10.2/100,000 males and 2.1/100,000 females
      2. asymptomatic laryngeal keratosis (leukoplakia) was not included in study

Table below derived from Isenberg, Crozier and Dailey (2008) "Institutional and comprehensive review of laryngeal leukoplakia" Ann otol Rhinol Laryngol 2008;117:74-9:

Leukoplakia	N	No Dysplasia	Mild/Mod Dysplasia	Severe Dysplasia/CIS
U of Wisconsin	208 biopsies 136 patietns	53%	18%	15%
15 publications	2,188 biopsies	53.6%	33.5%	15.2%

Noted discordance with confusion among pathologists regarding degree of dysplasia (Gupta 2010) and (El-Naggar AK 2017)

References

Gale et al “Epithelial precursor lesions” in Barnes et al (eds) Pathology and Genetics: head and neck tumours IARC Press 2005

Warnakulasuria et al: Nomenclature and classification of potentially malignant disorders of the oral mucosa. J Oral Pathol Med. 2007;36:575-80

Bouquot JE, Gnepp DR (1991) Laryngeal precursor: a review of the literature, commentary, and comparison with oral leukoplakia. Head Neck. 13:488-97

Bouquot et al  Cancer Detect Prev. 1991;15:83-91

Muller and Krohn J Cancer Res Clin oncol. 1980;96:211-7

Isenberg, Crozier and Dailey (2008) "Institutional and comprehensive review of laryngeal leukoplakia" Ann otol Rhinol Laryngol 2008;117:74-9

Gupta HT, Robinson RA, Murray RC, Karnell LH, Smith RJH and Hoffman HT: Degrees of Dysplasia and the Use of Cidofovir in Patients with Recurrent Respiratory Papillomatosis  Laryngoscope 120:698-702, 2010

El-Naggar AK, Chan JKC, Grandis JR, Takata Takashi, and Slootweg PJ: WHO Classification of Head and Neck Tumorurs. 4th Edition International Agency for Research on Cancer  lyon, 2017

Cosway B and Paleri V: Laryngeal dysplasia: An evidence-based flowchart to guide management and follow up The Journal of Laryngology & Otology (2015), 129, 598-599