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Lung

Salivary gland type tumors

Epithelial myoepithelial carcinoma

Author: Roseann I. Wu, M.D., M.P.H.

Last author update: 1 July 2017

Last staff update: 7 December 2023

Copyright: 2003-2024, PathologyOutlines.com, Inc.

PubMed Search: Epithelial myoepithelial carcinoma lung

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Table of Contents

Cite this page: Wu R. Epithelial myoepithelial carcinoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/lungtumorepithelialmyo.html. Accessed April 23rd, 2024.

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

Extremely rare in lung, case reports mostly in adults, rare case report in child (J Pediatr Hematol Oncol 2009;31:206)
No clear sex predominance

Sites

Bronchial tree, usually endobronchial but a few cases peripheral / parenchymal

Pathophysiology

Low grade malignancy with rare cases of metastasis to chest wall (Lung Cancer 2014;83:416), skull (Case Rep Oncol Med 2011;2011:610383) and lymph nodes (Hum Pathol 2009;40:366)

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

34 year old man with tracheal tumor (J Thorac Dis 2014;1:S194)
52 year old woman with progressive cough, dyspnea and wheezing (Case of the Week #357)
53 year old woman with tumor showing lobular solid growth and lymph node metastases (Tuberc Respir Dis (Seoul) 2015;78:428)
57 year old man with incidental endobronchial tumor (Case Rep Pathol 2012;2012:319434)
72 year old woman with tumor showing high grade transformation (Oncol Lett 2015;10:175)
73 year old man with bronchial tumor (Arch Pathol Lab Med. 2003 Apr;127:e177)

Treatment

Complete surgical resection
May recur after local therapy or incomplete excision (Clin Lung Cancer 2007;8:386)

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

Images hosted on other servers:

Incidental endobronchial mass

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