Lung tumor
Salivary gland type
Epithelial myoepithelial carcinoma


Topic Completed: 1 July 2017

Revised: 23 October 2019

Copyright: 2003-2019, PathologyOutlines.com, Inc.

PubMed Search: Epithelial myoepithelial carcinoma lung

Roseann Wu, M.D., M.P.H.
Page views in 2018: 1,632
Page views in 2019 to date: 1,352
Cite this page: Wu R. Epithelial myoepithelial carcinoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/lungtumorepithelialmyo.html. Accessed November 14th, 2019.
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

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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

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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

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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

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Contributed by Roseann Wu, M.D., M.P.H.

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Epithelial myoepithelial carcinoma arising from airway



Case of the Week #357:

Lung biopsy



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Tumor showing solid
mass in bronchus
and parenchyma
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Tumor with tubular and
glandular structures


Incidental endobronchial mass:
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H&E

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Calponin

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S100


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AE1/AE3

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CK7

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CK903

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Ki67

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

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