Esophagus

Other nonneoplastic

Epidermoid metaplasia


Editorial Board Members: Maryam Kherad Pezhouh, M.D., M.Sc., Raul S. Gonzalez, M.D.
Editor-in-Chief: Debra L. Zynger, M.D.
Yukihiro Nakanishi, M.D., Ph.D.

Last author update: 6 July 2022
Last staff update: 6 July 2022

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PubMed Search: Esophagus epidermoid metaplasia

Yukihiro Nakanishi, M.D., Ph.D.
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Cite this page: Nakanishi Y. Epidermoid metaplasia. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/esophagusepidermization.html. Accessed December 3rd, 2022.
Definition / general
  • Esophageal squamous epithelium with a prominent granular layer and orthokeratosis / hyperorthokeratosis, resembling the epidermis of the skin
Essential features
  • Affects middle aged to elderly individuals with a history of smoking and alcohol intake
  • Well demarcated white plaque in the mid to distal esophagus
  • Esophageal squamous epithelium with a prominent granular layer and orthokeratosis / hyperorthokeratosis
  • Possible association with esophageal squamous cell carcinoma and dysplasia
  • Follow up, unless a patient has a concurrent squamous cell carcinoma
Terminology
  • Also known as epidermization, esophageal leukoplakia, orthokeratosis and hyperkeratosis
ICD coding
  • ICD-10: K22.9 - Disease of esophagus, unspecified
Epidemiology
Sites
Etiology
Clinical features
  • Dysphagia or asymptomatic
  • Endoscopy findings
    • Scaly or shaggy white plaque with clear borders
    • Mimics crackleware china
    • Lugol voiding lesion with clear demarcation, resembling superficial esophageal cancer (Hepatogastroenterology 2011;58:809)
Diagnosis
  • Diagnosis is based on esophageal biopsy histologic findings
Case reports
Treatment
  • Follow up, unless a patient has a concurrent squamous cell carcinoma
Clinical images

Images hosted on other servers:

Scaly white plaque

Gross description
Microscopic (histologic) description
  • Esophageal squamous epithelium with a compact layer of orthokeratosis / hyperorthokeratosis and a prominent granular layer 1 - 4 cells thick with keratohyalin granules, resembling the epidermis of the skin
  • Abrupt transition from the adjacent normal squamous epithelium
  • Reference: Am J Surg Pathol 1997;21:605
Microscopic (histologic) images

Contributed by Yukihiro Nakanishi, M.D., Ph.D.

Orthokeratosis /
hyperorthokeratosis

Prominent granular layer

Positive stains
Molecular / cytogenetics description
  • Targeted next generation sequencing analysis of epidermoid metaplasia shows frequently mutated genes consisted of TP53, PIK3CA, EGFR, MYCN, HRAS and the TERT promoter (Mod Pathol 2017;30:1613)
Sample pathology report
  • Esophagus, mid, plaque, biopsy:
    • Epidermoid metaplasia / epidermization / orthokeratosis with prominent granular layer
    • Negative for dysplasia or malignancy
Differential diagnosis
  • Hyperkeratosis:
    • No prominent granular layer
  • Parakeratosis:
    • Nuclei present in a keratin layer without an associated prominent granular layer
  • Dysplasia:
    • Variable nuclear atypia present
  • Squamous cell carcinoma in situ:
    • Full thickness nuclear atypia present
  • Atrophic change:
    • No orthokeratosis or prominent granular layer
Additional references
Board review style question #1
Which of the following statements about epidermization / epidermoid metaplasia of the esophagus is true?

  1. Characterized by orthokeratosis / hyperorthokeratosis with a prominent granular layer
  2. No association with smoking or excessive alcohol consumption
  3. No association with squamous cell carcinoma and dysplasia
  4. PAS stain highlights epidermoid metaplasia
Board review style answer #1
A. Epidermization / epidermal metaplasia is characterized by orthokeratosis / hyperorthokeratosis with a prominent granular layer, mimicking epidermis.

Comment Here

Reference: Epidermoid metaplasia
Board review style question #2

Which of the following statements about histologic features of epidermization / epidermoid metaplasia of the esophagus is true?

  1. Characterized by the presence of the stratum lucidum beneath the cornified layer
  2. Finding of increased thickness in the cornified layer is called parakeratosis
  3. Granular layer is characterized by the presence of basophilic stained granules known as keratohyalin granules
  4. Orthokeratosis / hyperkeratosis is more frequently seen in the esophagus than parakeratosis
Board review style answer #2
C. Epidermization / epidermoid metaplasia is histopathologically characterized by the presence of the granular layer beneath the cornified layer. The granular layer contains basophilic stained granules known as keratohyalin granules. Parakeratosis is characterized by keratosis with persistence of the cell nuclei. The stratum lucidum is seen only in soles and palms and is not seen in epidermization / epidermoid metaplasia. Parakeratosis is more frequently seen in the esophagus than orthokeratosis / hyperkeratosis.

Comment Here

Reference: Epidermoid metaplasia
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