|Year : 2022 | Volume
| Issue : 2 | Page : 98-100
Primary epithelial–myoepithelial carcinoma of the lung: Reporting a rare entity at a rare location
Deepak Uppal1, Divya Khosla1, Debajyoti Chatterjee2, Vrinda Singla1, Divyesh Kumar1, Renu Madan1, Rakesh Kapoor1
1 Department of Radiotherapy, Postgraduate Institute of Medical Education and Research, Regional Cancer Centre, Chandigarh, India
2 Department of Histopathology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
|Date of Submission||20-Oct-2020|
|Date of Acceptance||05-Apr-2021|
|Date of Web Publication||22-Jul-2022|
Dr. Divya Khosla
Department of Radiotherapy, Postgraduate Institute of Medical Education and Research, Regional Cancer Centre, Chandigarh
Source of Support: None, Conflict of Interest: None
Epithelial–myoepithelial carcinoma (EMC) of the lung is a rare neoplasm, constituting about 0.1%–1% of all primary lung cancers. EMC usually has an indolent course with occasional distant metastasis. A 52-year-old male presented with an unresectable lesion in the upper lobe of the right lung with mediastinal lymph nodes. Bronchoscopic biopsy and detailed histopathological examination revealed an EMC of the lung. Due to advanced disease and poor performance status of the patient, he was treated with palliative radiation followed by palliative chemotherapy. However, the patient succumbed to the disease after two cycles of palliative chemotherapy. Experience with EMC of the lung is limited and optimal treatment protocols have not been defined, with current treatment mainly extrapolated from EMC of the salivary glands from the head and neck. We add another case to the limited literature of EMC of the lung.
Keywords: Epithelial–myoepithelial carcinoma, lung, radiotherapy
|How to cite this article:|
Uppal D, Khosla D, Chatterjee D, Singla V, Kumar D, Madan R, Kapoor R. Primary epithelial–myoepithelial carcinoma of the lung: Reporting a rare entity at a rare location. Int J Non-Commun Dis 2022;7:98-100
|How to cite this URL:|
Uppal D, Khosla D, Chatterjee D, Singla V, Kumar D, Madan R, Kapoor R. Primary epithelial–myoepithelial carcinoma of the lung: Reporting a rare entity at a rare location. Int J Non-Commun Dis [serial online] 2022 [cited 2022 Aug 8];7:98-100. Available from: https://www.ijncd.org/text.asp?2022/7/2/98/351748
| Introduction|| |
Epithelial–myoepithelial carcinoma (EMC) is an uncommon malignancy. It constitutes about 1%–2% of all salivary gland neoplasms.,, Lung is a rare site of primary EMC, accounting for 0.1%–1% of all primary lung cancers. It is considered as low-grade malignancy with indolent course and with occasional nodal and distant metastasis. Epithelial–myoepithelial tumors histologically consist of inner epithelial cells with an outer layer of myoepithelial cells., Less than sixty cases of EMC of the lung have been reported in literature. To the best of our knowledge, this is the first case of primary EMC of the lung from India. Herein, we report a rare case of EMC of the lung in a 52-year-old male from northern India along with review of literature.
| Case Report|| |
A 52-year-old male presented with complaints of pain in the right upper chest, dry cough, and shortness of breath on exertion for 5 months. There were no complaints of fever, weight loss, night sweats, hemoptysis, or pain anywhere else in the body. He was a chronic smoker with history of 30 pack years and chronic alcoholic.
Contrast-enhanced computed tomography (CECT) of the chest indicated a lobulated soft attenuation lesion measuring 7 cm × 5 cm showing heterogeneous postcontrast enhancement with nonenhancing necrotic areas in the right upper lobe reaching up to the right horizontal fissure with right hilar and suprahilar extension further invading adjacent pleura and mediastinum. The lesion was abutting the superior vena cava and right brachiocephalic vein without any obvious invasion. Few subcentimetric mediastinum lymph nodes were also seen.
Bronchoscopy revealed a right upper lobe mass completely occluding its opening. Endobronchial biopsy revealed focal respiratory lining epithelium. Subepithelium showed a tumor arranged in the form of closely packed nests separated by thin septae [Figure 1]a. The nests are composed of inner layer of epithelial cells with clear cytoplasm and peripheral layer of basaloid myoepithelial cells [Figure 1]b. Individual tumor cells consisted of moderately pleomorphic nuclei, inconspicuous nucleoli and scant to moderate amount of clear to eosinophilic cytoplasm. No necrosis or atypical mitosis was seen. On immunohistochemistry, PAX8, CD 56, and TTF were negative. The epithelial cells were highlighted by CK7 [Figure 1]c and the myoepithelial cells were highlighted by p63 [Figure 1]d. The final impression was of EMC.
|Figure 1: (a) Lung biopsy shows a tumor in the subepithelium arranged in nests (hematoxylin and eosin, ×100). (b) The nests are composed of inner layer of epithelial cells with clear cytoplasm and peripheral layer of basaloid myoepithelial cells (hematoxylin and eosin, ×200). (c) The epithelial cells are highlighted by cytokeratin 7 (immunohistochemistry, ×100). (d) p63 highlights the myoepithelial cells at the periphery of each nest (immunohistochemistry, ×100)|
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Positron emission tomography was also done, which showed heterogeneous fluorodeoxyglucose (FDG)-avid ill-defined enhancing soft tissue mass in the right hilar and suprahilar region with collapse of the right upper lobe abutting and partially encasing superior vena cava and right pulmonary artery. FDG-avid lesions in the right lower lobe, subcentimetric bilateral upper and lower paratracheal, thoracic, paraaortic, precarinal, subcarinal, bilateral hilar, and interlobar lymph nodes were also present. In view of the Eastern Cooperative Oncology Group (ECOG) performance status 2, the patient was given palliative radiation of 30 Gy in 10 fractions to the right lung lesion. After monthly follow-up, the patient had 50% subjective symptomatic relief. He was started on palliative chemotherapy with single-agent paclitaxel, but his condition deteriorated and he died of progressive disease.
| Discussion|| |
The submucosa of the trachea–bronchial tree consists of glands which are similar to the minor salivary glands of the head and neck region. EMC of the lung is the neoplasm of these submucosal glands and is a rare neoplasm. It demonstrates a biphasic pattern of cell population consisting of an inner layer of duct-like epithelial cells and outer layer of myoepithelial cells. Immunohistochemically, the epithelial component stains positive for cytokeratin, CK7, whereas myoepithelial cells show positivity for S-100, p63, and CD10. In the case being discussed in this report, the epithelial cells were highlighted by CK7 and myoepithelial cells by p63.
To the best of our knowledge, less than 60 cases have been reported so far in the literature and this is the first case from India. It occurs mostly in middle-aged people with female preponderance. Smoking as an etiological factor has not been proven so far as it has been reported in both smokers and nonsmokers. Most of the cases had tumors with epicenter in the central airway presenting as endobronchial masses; however, parenchymal location has also been reported. Grossly, these tumors are well defined nonencapsulated masses. In the reviewed literature, about 80% of the patients had tumor located in the central airway and about 20% had tumors originating in the lung parenchyma.,,, The case being reported here is middle-aged male with chronic smoking history and having a mass in the right hilar and suprahilar location.
Pulmonary EMC has been described by some as a neoplasm with uncertain malignant potential. The chance of relapse seems to increase with tumor having adverse features such as large size, positive margins, lymphovascular invasion, myoepithelial anaplasia, and necrosis., The differential diagnosis of pulmonary EMC includes mucoepidermoid carcinoma, acinic cell carcinoma, pulmonary pleomorphic adenoma, adenoid cystic carcinoma, myoepithelioma, myoepithelial carcinoma, metastasis from head and neck minor salivary gland EMC, and primary and metastatic clear cell carcinomas.,
Due to rarity of pulmonary EMC, optimal treatment strategies have not been established yet. Studies with longer follow-ups are required to establish the biological behavior of the tumor and the optimal therapy. Considering the long interval between diagnosis and recurrence in minor salivary glands tumor and expecting a similar behavior, complete resection seems to be the treatment of choice. Tumors with adverse features may require adjuvant treatment with radiotherapy and chemotherapy, although their respective role as a treatment option and effect on prognosis is yet to be established. The index case being reported was unresectable with ECOG performance status 2 and was treated with a palliative intent.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
| Conclusion|| |
Pulmonary EMC is a rare neoplasm with uncertain malignant potential, and cases with locoregional and distant metastasis have been reported. Complete resection is the treatment of choice. Further studies with longer follow-up periods are needed to know the biological behavior of the tumor and establish an optimal treatment strategy.
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Conflicts of interest
There are no conflicts of interest.
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