Larynx, hypopharynx & trachea

Precursor epithelial lesions


Last author update: 1 November 2013
Last staff update: 30 June 2022

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PubMed Search: Dysplasia larynx

Nat Pernick, M.D.
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Cite this page: Pernick N. Dysplasia. website. Accessed September 25th, 2023.
Definition / general
  • For columnar epithelium, resembles cervical dysplasia
  • Associated with HPV 16 and p53 expression
  • Leukoplakia: clinical term describing any white lesion on a mucous membrane; usually associated with mucosal thickening and not dysplasia
  • Erythroplakia: clinical term describing red lesion on a mucous membrane; usually associated with dysplasia or malignancy; in smokers, for squamous epithelium, features of nuclear pleomorphism, mitotic activity, abnormal mitotic figures and stromal inflammation are associated with progression to invasive carcinoma
  • Keratosis: increase in surface keratin, often with prominent granular cell layer and orthokeratin (cells without nuclei) mixed with parakeratin (flat keratotic cells with pyknotic nuclei); not related to dysplasia
  • Dyskeratosis: abnormal keratinization of epithelial cells
  • Dysplasia: spectrum of abnormal epithelial maturation and cellular atypia that may or may not precede invasive carcinoma
  • Carcinoma in situ: full thickness dysplasia of mucosa without violation of basement membrane; same as severe dysplasia
Prognostic factors
  • Overall, low risk of development of invasive squamous cell carcinoma after dysplasia
  • For mild dysplasia, 7% develop in situ or invasive carcinoma versus 24% with moderate dysplasia versus 25% with severe dysplasia
  • High risk of progression to invasive carcinoma for severe keratinizing dysplasia versus nonkeratinizing dysplasia
  • Mild / moderate dysplasia may be reversible
  • Severe dysplasia requires intervention (vocal cord stripping, surgery, radiation therapy, endoscopic laser resection) as well as surveillance of entire upper aerodigestive tract
Gross description
  • Erythema of involved areas
Microscopic (histologic) description
  • Mild dysplasia:
    • Normal or mildly disordered basal layer with retained maturation and stratification of upper layers
    • Mild nuclear atypia and possibly mitotic figures in basal third of epithelium
    • No abnormal mitotic figures
    • Variable keratosis and chronic inflammatory infiltrate
  • Moderate dysplasia:
    • Moderate nuclear atypia, usually with prominent nucleoli and mitotic figures, most pronounced in lower two - thirds of epithelium
    • Cell maturation and stratification are present in upper layer
    • No abnormal mitotic figures
    • Variable keratosis
  • Severe / high grade:
    • Marked nuclear abnormalities and loss of maturation greater than two - thirds of epithelium
    • Large atypical nuclei, some bizarre; nuclear pleomorphism is common
    • May have prominent nucleoli
    • Mitotic figures high in epithelium, often abnormal
  • Keratinizing dysplasia:
    • Defined as lesions in which epithelial alterations are so severe that there is a high probability of progression to invasive carcinoma
    • Includes dyskeratotic cells and mitotic figures with variable atypical forms above basal zone, variable surface keratinization
  • Carcinoma in situ:
    • Full thickness nuclear abnormalities without stromal invasion
    • Cells are usually keratinized but may be basal-like
    • Often lumped together with severe dysplasia
    • May represent peripheral portion of invasive carcinoma
  • Papillary carcinoma in situ:
    • Papillary fronds with a fibrovascular core covered by squamous epithelium with marked atypia
  • Note: invasion may occur by dysplastic cells without full thickness epithelial involvement
Additional references
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