Lung
Salivary gland type tumors
Epithelial myoepithelial carcinoma


Topic Completed: 1 July 2017

Minor changes: 22 December 2020

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PubMed Search: Epithelial myoepithelial carcinoma lung

Roseann Wu, M.D., M.P.H.
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Cite this page: Wu R. Epithelial myoepithelial carcinoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/lungtumorepithelialmyo.html. Accessed May 8th, 2021.
Definition / general
  • Low grade malignancy that arises from submucosal bronchial glands, mimics similar salivary gland tumor
  • Very rare in lung, only case reports and small series
  • Long interval to recurrence or metastasis
Essential features
  • Rare, low grade, primary salivary gland-type carcinoma of the lung
  • Typically arises in bronchial tree from submucosal glands
  • Characterized by biphasic proliferation of duct-like epithelial cells with surrounding myoepithelial cells
Terminology
  • Previous designations include adenomyoepithelioma, epithelial myoepithelial tumor, epithelial myoepithelial tumor of unknown malignant potential, pneumocytic adenomyoepithelioma (Hum Pathol 2009;40:366, Mod Pathol 2001;14:521)
ICD coding
  • C33 Malignant neoplasm of trachea
  • C34.00 Malignant neoplasm of unspecified main bronchus
  • C34.01 Malignant neoplasm of right main bronchus
  • C34.02 Malignant neoplasm of left main bronchus
  • Code more peripheral lesions depending on specific lobe, laterality and extent
Epidemiology
Sites
  • Bronchial tree, usually endobronchial but a few cases peripheral / parenchymal
Pathophysiology
Etiology
  • Arises from submucosal bronchial glands, the lung counterpart of the intercalated duct of the salivary gland (Oncol Lett 2015;10:175)
Clinical features
  • Cough, hemoptysis, dyspnea or obstructive symptoms if endobronchial location
  • Peripheral lesions may be asymptomatic
Diagnosis
  • Challenging to diagnose with small biopsy specimens
  • Exclude metastasis from salivary gland
Radiology images

Images hosted on other servers:
Chest Xray and<br>CT of peripheral nodule

Chest Xray and
CT of peripheral nodule

Prognostic factors
  • Complete surgical resection generally curative
  • High mitotic rate, tumor necrosis and nuclear pleomorphism appear to be adverse prognostic factors (Am J Surg Pathol 2001;25:1508)
Case reports
Treatment
Clinical images

Images hosted on other servers:
Bronchoscopy with lobulated<br>endobronchial mass

Bronchoscopy with lobulated
endobronchial mass

Gross description
  • Intraluminal polypoid mass in bronchus; may invade parenchyma
  • Well circumscribed, unencapsulated, tan, firm
  • Variable size averaging a few centimeters
Gross images

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Incidental endobronchial mass

Incidental endobronchial mass

Peripheral tumor

Peripheral tumor

Microscopic (histologic) description
  • Well circumscribed mass with pushing margin
  • Thin fibrous septa with variable hyalinization or sclerosis
  • Biphasic proliferation of inner epithelial and outer myoepithelial cells with formation of bilayered, duct-like structures
  • Appearance and proportion of two cell types may be variable
  • Epithelial cells flattened, cuboidal or columnar with somewhat clear to eosinophilic cytoplasm
  • Myoepithelial cells may be indistinct, flattened, spindled or clear
  • Lumens may contain pale to eosinophilic amorphous material or debris
  • Scant inflammatory infiltrate may be present
  • Mitoses, significant nuclear atypia, necrosis and hemorrhage typically absent
Microscopic (histologic) images

Contributed by Roseann Wu, M.D., M.P.H. and Case #357
Epithelial myoepithelial carcinoma arising from airway Epithelial myoepithelial carcinoma arising from airway

Epithelial myoepithelial carcinoma arising from airway

Lung biopsy Lung biopsy Lung biopsy Lung biopsy

Lung biopsy


Lung biopsy

Lung biopsy



Images hosted on other servers:
Tumor with tubular and<br>glandular structures

Tumor with tubular and
glandular structures

Incidental endobronchial mass - H&E Incidental endobronchial mass - H&E

Incidental endobronchial mass - H&E

Incidental endobronchial mass - calponin

Incidental endobronchial mass - calponin

Incidental endobronchial mass - S100

Incidental endobronchial mass - S100

Incidental endobronchial mass - AE1 / AE3

Incidental endobronchial mass - AE1 / AE3


Incidental endobronchial mass - CK7

Incidental endobronchial mass - CK7

Incidental endobronchial mass - CK903

Incidental endobronchial mass - CK903

Incidental endobronchial mass - Ki67

Incidental endobronchial mass - Ki67

Positive stains
Negative stains
Molecular / cytogenetics description
Differential diagnosis
Additional references
Board review style question #1
    Epithelial myoepithelial carcinoma primary to the lung is believed to arise from what cell type(s)?

  1. Club cells
  2. Ciliated columnar cells
  3. Submucosal bronchial glands
  4. Type 1 pneumocytes
  5. Type 2 pneumocytes
Board review style answer #1
C. Submucosal bronchial glands
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