Pulmonary epithelial-myoepithelial carcinomas are rare low-grade malignant neoplasms with histologic features similar to their salivary gland counterparts. We report a series of 5 cases and describe their clinical, morphological, and immunohistochemical features. The patients included 3 men and 2 women whose ages ranged from 38 to 56 years. All patients had obstructing endobronchial lesions that ranged from 2.5 to 5.0 cm in greatest dimension. The tumors were completely resected by simple lobectomy or pneumonectomy. In one patient, the tumor infiltrated perinodal soft tissue of a peribronchial lymph node with intranodal extension and metastasis within the same lymph node. The follow-up in these patients ranged from 4 to 12 months. The histologic appearance of these tumors varied, but all shared the common feature of a biphasic proliferation of epithelial (strong cytokeratin-positive; actin and S-100-negative) and myoepithelial (strong actin and S-100 and focal weak cytokeratin-positive) cells with formation of bilayered ductlike structures. The focal resemblance to other salivary gland-type tumors may cause diagnostic difficulties, particularly in small endobronchial biopsies. Although little is known about their biologic potential due to limited follow-up data, these tumors when in the lung clearly have the capacity to infiltrate and metastasize and therefore should be designated as epithelial-myoepithelial carcinoma. At present, it appears that treatment by complete surgical resection with negative margins alone is appropriate and adequate.
"To date, 24 cases have been reported in the lung, variably classified as “adenomyoepithelioma”, “pneumocytic adenomyoepithelioma”, “myoepithelioma”, “epithelial myoepithelial carcinoma”, and epithelial myoepithelial tumor. One suggested term by Pelosi was pulmonary epithelial myoepithelial tumor of unproven malignant potential (PEMTUMP) [7, 12]. "
[Show abstract][Hide abstract] ABSTRACT: Primary epithelial myoepithelial carcinoma of lung is a rare entity and is thought to arise from the submucosal bronchial glands distributed throughout the lower respiratory tract. Because of the rarity of this tumor, we describe one case of epithelial myoepithelial carcinoma arising in the bronchus intermedius and presenting as an endobronchial mass. A 57-year-old male patient presented with an incidental finding of an endobronchial mass located in the lumen of the right lower lobe bronchus and caused near total luminal occlusion of the bronchus. An endobronchial carcinoid tumor was entertained clinically. Subsequently the patient underwent an uneventful videothoracoscopic lobectomy of lower and middle lobes of the right lung. Morphologically and immunohistochemically the tumor was characterized by two cell populations with epithelial and myoepithelial cells forming duct-like structure. The final diagnosis of epithelial myoepithelial carcinoma of lung was rendered.
"The symptoms are very varied, ranging from asymptomatic cases, as the one we are presenting, to cough, haemoptysis, thoracic pain, fever , dyspnoea, pneumonia , recurrent infections and others. All patients evolved satisfactorily, without signs of recurrence nor metastases, and with no need for adjuvant chemo or radiotherapy, although recently Nguyen et al. have included the first description of a case of peribronchial lymph node metastases in a series of five cases . One of the patients died because of a carcinoma of the floor of the mouth 36 months after the diagnose of epithelial-myoepithelial tumour of the lung was made . "
[Show abstract][Hide abstract] ABSTRACT: Tracheobronchial submucous glands can be considered the pulmonary equivalent of minor salivary glands and therefore they can develop most of the tumours originated in these. Nevertheless, in spite of the wide distribution of this kind of glands along the tracheobronchial tree, pulmonary salivary gland-like neoplasms are not very frequent. Among them, the most frequent are mucoepidermoid and adenoid cystic carcinomas. On the contrary, pulmonary neoplasms showing a mixture of epithelial and myoepithelial elements are extraordinary infrequent, with only 11 cases collected from literature.
We present the case of a 76 year-old woman with no interesting pathological history, to whom a pulmonary nodule is detected during a study of unknown origin neutropenia. An upper right lobectomy is performed.
After macro and microscopic study, the diagnosis of pulmonary epithelial-myoepithelial tumour is made. It is a low malignant potential tumour with capacity to locally recur and less frequently to metastasize. Our case has the peculiarity of not being connected neither to visceral pleura nor to bronchial tree; we have not found this characteristic in any literature reviewed case.
These tumours have been named in a lot of different ways, including adenomyoepithelioma, epithelial-myoepithelial tumour, epithelial-myoepithelial carcinoma or epithelial-myoepithelial tumour of uncertain malignant potential.
The p27/kip-1 protein plays a fundamental role in the development of these neoplasms. As we have verified in our case, its aberrant cytoplasmic location, besides its proved oncogenic function, would favour the proliferation of stem cells, which would explain both dual phenotype with presence of myoepithelial cells without connection with the bronchial tree, and TTF-1 immunostaining in epithelial cells.
"Histologically, all lesions share the common features of having duct-like structures within a background of variable proportions of epithelial and myoepithelial cells . The inner layer consists of small darker cuboidal epithelial cells (positive for cytokeratin, negative for S-100 and muscle-specific actin), while the outer layer is formed by clear myoepithelial cells (positive for S-100, muscle-specific actin, and P63 with focal weak positivity for cytokeratin)    . As to the malignant potential of pulmonary EMC, samples obtained from the primary and metastatic regions in our case did not show prognostic factors such as mitoses or necrosis. "
[Show abstract][Hide abstract] ABSTRACT: Epithelial-myoepithelial carcinoma (EMC) of the lung is rare and is considered to be low-grade malignancy. Intracranial metastasis of pulmonary EMC has not previously been reported according to our search of the literature. We report a case of skull metastasis as the initial manifestation of pulmonary EMC. An 81-year-old man complained of left leg motor weakness. Neurological examination showed left hemiparesis. Computed tomography and magnetic resonance imaging revealed an osteolytic tumor in the right frontal bone with invasion to the dura and subdural space, attached to the superior sagittal sinus. Subtotal removal of the tumor was performed, and the left hemiparesis showed improvement. Histopathological study revealed the tumor to consist of epithelial and myoepithelial cells. Pulmonary EMC was diagnosed. The MIB-1 index in primary lesion was approximately 10%. The skull and dura are possible sites for metastasis from pulmonary EMC. The MIB-1 index is a predictive marker of malignant potential.
Case Reports in Oncological Medicine 07/2011; 2011:610383. DOI:10.1155/2011/610383
Sang Yull Kang, Seon Kwang Kim, Hyun Jo Youn, Sung Hoo Jung
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