Thoracic myoepithelial tumors: A pathologic and molecular study of 8 cases with review of the literature Journal Article


Authors: Leduc, C.; Zhang, L.; Öz, B.; Luo, J.; Fukuoka, J.; Antonescu, C. R.; Travis, W. D.
Article Title: Thoracic myoepithelial tumors: A pathologic and molecular study of 8 cases with review of the literature
Abstract: Thoracic myoepithelial tumors (MTs) are a rare group of tumors showing predominant or exclusive myoepithelial differentiation. They are poorly characterized from both a morphologic and genetic standpoint, in particular features that separate benign from malignant behavior. We examined the histologic and immunohistochemical features of 8 primary thoracic MTs and performed fluorescence in situ hybridization for EWSR1, FUS, PLAG1, and HMGA2, as well as several partner genes. Half (4/8) of the MTs occurred in large airways, and 3 had infiltrative borders. All cases showed immunoreactivity for epithelial markers, in conjunction with S100 protein or myogenic markers. MTs showed morphologic characteristics analogous to MTs at other sites, with no tumors having ductal differentiation. Necrosis and/or lymphovascular invasion was present in 5 cases, with mitotic activity ranging from 0 to 6 mitoses/2mm2 (mean 1). Metastases occurred in 2 cases, and no patients died of disease. Gene rearrangements were identified in half of the cases, with EWSR1-PBX1, EWSR1-ZNF444, and FUS-KLF17 fusions identified in 1 case each and 1 case having EWSR1 rearrangement with no partner identified. No cases were found to have HMGA2 or PLAG1 abnormalities. Compared with fusion-negative tumors, fusionpositive tumors tended to occur in patients who were younger (50 vs. 58 y), female (1:3 vs. 3:1 male:female ratio), and demonstrated predominantly spindle and clear cell morphology. Using a combined data set of our case series with 16 cases from the literature, poor prognosis was significantly correlated with metastases (P=0.003), necrosis (P=0.027), and ≥5 mitoses/2mm2/10 high-power field (P=0.005). In summary, we identify a subset of thoracic MTs harboring rearrangements in EWSR1 or FUS, and our data suggest that necrosis and increased mitotic activity correlate with aggressive clinical behavior. © 2015 Wolters Kluwer Health, Inc. All rights reserved.
Keywords: myoepithelioma; myoepithelial carcinoma; fus; ews; klf17; myoepithelial tumor; pbx1; znf444
Journal Title: American Journal of Surgical Pathology
Volume: 40
Issue: 2
ISSN: 0147-5185
Publisher: Lippincott Williams & Wilkins  
Date Published: 2016-02-01
Start Page: 212
End Page: 223
Language: English
DOI: 10.1097/pas.0000000000000560
PROVIDER: scopus
PUBMED: 26645726
PMCID: PMC5006686
DOI/URL:
Notes: Article -- Export Date: 3 March 2016 -- Source: Scopus
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MSK Authors
  1. Cristina R Antonescu
    895 Antonescu
  2. William D Travis
    743 Travis
  3. Lei Zhang
    194 Zhang
  4. Charles   Leduc
    13 Leduc