Epithelial-myoepithelial carcinoma of the lung. A case report and review of the literature

White out hemithorax secondary to salivary gland type of lung cancer with metastasis in liver and bone: a case report

BACKGROUND

Salivary gland-type lung carcinomas are uncommon neoplasms of the lung, representing less than 1% of all lung tumors. The two most common among them are adenoid cystic carcinoma and mucoepidermoid carcinoma. Although they usually have an indolent behavior, adenoid cystic carcinomas can be more aggressive, with 5-year survival as low as 55%. Very few cases are reported in literature. We report a similar rare case of salivary gland type lung carcinoma that presented for the first time with unilateral opacification of left hemithorax.

CASE PRESENTATION

A 38-year-old man of North Indian origin, who was a a nonsmoker, presented with complaints of shortness of breath and cough for 1 year, which has increased in the last 2 months and was associated with significant weight loss. A frontal radiograph of the chest and computed tomography of the chest were performed, which showed a mass in the left upper lobe of the lung with its epicenter in the left main bronchus. A bronchoscopic guided biopsy was performed, and histopathology confirmed the diagnosis of lung carcinoma of salivary gland type (adenoid cystic carcinoma). There was invasion of major vessels, hence the patient was offered and started on palliative management instead of surgical treatment. In spite of palliative management of two cycles of chemotherapy and radiotherapy, the patient succumbed to the disease within 2 months from the time of diagnosis.

CONCLUSION

Lung carcinoma of the salivary gland type (especially adenoid cystic carcinoma) usually presents at a later stage. The resectability of the tumor depends on the involvement of the surrounding major vessels. Interestingly, these cancers have no association with smoking. The prognosis depends on the extent of the disease at the time of diagnosis. Hence, imaging plays a major role in deciding the further plan of management.

Recent developments in the pathology of primary pulmonary salivary gland-type tumours

Primary pulmonary salivary gland-type tumours are rare neoplasms that are thought to arise from seromucinous glands that are located in the submucosa of large airways. These neoplasms have clinical and pathologic features that are distinct from other pulmonary neoplasms. The majority of primary pulmonary salivary gland-type tumours are malignant, with the most common entities being mucoepidermoid carcinoma, adenoid cystic carcinoma, and epithelial-myoepithelial carcinoma. Less commonly seen are myoepithelial carcinoma, hyalinizing clear cell carcinoma, acinic cell carcinoma, secretory carcinoma, salivary duct carcinoma, intraductal carcinoma, and polymorphous adenocarcinoma. Benign salivary gland-type tumours of the lung include pleomorphic adenoma and sialadenoma papilliferum. Morphologic, immunophenotypic, and molecular features of these neoplasms are largely similar to salivary gland tumours elsewhere, and therefore the exclusion of metastatic disease requires clinical and radiologic correlation. However, the differential diagnostic considerations are different in the lung. The distinction of salivary gland-type tumours from their histologic mimics is important for both prognostication and treatment decisions. Overall, salivary gland type-tumours tend to have a more favourable outcome than other pulmonary carcinomas, although high-grade variants exist for many of these tumour types. Recent advances in our understanding of the spectrum of salivary gland-type tumours reported in the lung and their diversity of molecular and immunohistochemical features have helped to refine the classification of these tumours and have highlighted a few differences between salivary gland-type tumours of the lung and those primary to other sites.

Pulmonary Epithelial-Myoepithelial Carcinoma

Pulmonary epithelial-myoepithelial carcinoma (P-EMC) is an exceptionally rare subtype of salivary gland lung tumor originating from tracheobronchial glands. P-EMC is a biphasic tumor consisting of an inner layer of epithelial cells and an outer layer of spindle-shaped, clear-cell-like myoepithelial cells. Bronchial obstruction symptom is the main clinical characteristic for P-EMC. Because its clinical and imaging characteristics are highly similar to other types of non-small-cell lung cancer (NSCLC), it is easy to cause missed diagnosis and misdiagnosis. The diagnosis is mainly based on the pathology and immunohistochemistry with an inner layer of epithelial cells immunoreactive for cytokeratin and an outside layer of myoepithelial cells immunoreactive for S100 protein (S-100) and smooth muscle actin (SMA). Therefore, positive for cytokeratin, S-100 and SMA can assist in the diagnosis. Although in general, P-EMC is a low-grade malignant neoplasm, it may occasionally recur and metastasize. The optimal method for P-EMC treatment has not been established, and surgical resection is still the main clinical method. Radiotherapy and chemotherapy have been shown not sensitive for P-EMC treatment, whereas targeted therapy and immunotherapy have not evaluated in clinical practice. This review focuses on the pathological characteristics, molecular characteristics, diagnosis, treatment, and prognosis of P-EMC.

The First Reported Pediatric Case of Primary Myoepithelial Carcinoma Involving the Whole Lung: Surgical Radical Treatment and Prosthesis Implant

Primary myoepithelial carcinoma of the lung (PMC-L) arising from the bronchial glands in lower respiratory tract is exceedingly rare. Thus far, few cases in adults and only one in a pediatric patient have been recorded. To our knowledge, this is the first report of PMC-L successfully removed in a child, focusing on the importance of multidisciplinary primary surgery for the treatment of this tumor. A 7-year-old girl was admitted for persistent cough and fever; she was unresponsive to oral antibiotics. Chest radiography showed loss of volume of left lung sustained by almost total atelectasis. After routine clinical investigations, she was referred for computed tomography scan and magnetic resonance imaging that documented the presence of a mass occupying the entire left upper lobe, infiltrating the pulmonary hilum (main bronchus, pulmonary artery, superior pulmonary vein, and pericardium). After multidisciplinary evaluation, the histopathologic diagnosis of PMC-L was established using ultrasonography-guided transthoracic core needle biopsy and bronchoscopic biopsies. She was then subjected to left pneumonectomy under extracorporeal circulation and positioning of a thoracic expander filled with 200 mL of saline solution. The postoperative course was uneventful. With TREP (very Rare Tumor in Pediatric Age) consent radiotherapy was performed (61.2 Gy). At the 10-month follow-up, the patient was alive, breathing normally without any oxygen support, without recurrence of PMC-L or metastasis, and without any chest deformity. To our knowledge, this is the first case where a pediatric patient was successfully operated for PMC-L involving the whole lung. Extracorporeal circulation enabled us to perform radical primary surgery. Prosthesis implant not only maintained normal chest expansion but also allowed focused radiotherapy, thus enabling us to prevent damage to vital organs.

Fine-needle aspiration cytology of the apocrine variant of epithelial-myoepithelial carcinoma

Epithelial‐myoepithelial carcinoma (EMCa) is a rare neoplasm that most frequently afflicts the parotid gland. Histologically, a dual layer of inner, luminal epithelial cells and outer myoepithelial cells with associated background hyalinization characterize these tumors. Several variants of EMCa have been described, including the more recent description of the apocrine variant. We present here a case of a 71‐year‐old male with a parotid mass diagnosed on FNA as an apocrine epithelial‐myoepithelial carcinoma. To our knowledge, this is the first case report describing the cytomorphologic features of apocrine EMCa on FNA smears.

Epithelial-myoepithelial carcinoma of the lung: a case report

BACKGROUND

Pulmonary epithelial-myoepithelial carcinoma (P-EMC) is a rare subset of salivary gland-type tumors of the lung. Because of its rarity and unproven malignant potential, the optimal therapy for P-EMC has not been defined. Here, we report a typical case of P-EMC and a review of the literature to consider appropriate treatment.

CASE PRESENTATION

A 54-year-old woman presented with an abnormal lung shadow on a routine chest X-ray. A chest computed tomography (CT) scan verified an 18-mm endobronchial nodule on the middle lobe. We performed a bronchoscopic biopsy, and the patient was diagnosed with P-EMC. After confirming the absence of tumors in the salivary glands, she underwent a right middle lobectomy along with hilar and mediastinal lymph node dissections. Currently, the patient is doing well, without any sign of recurrence 3 years after surgery.

CONCLUSIONS

Although a majority of P-EMC cases, as in our case, behave indolently, several poor progression cases have been reported. For distinguishing the minor malignancy cases from others, histological findings such as myoepithelial anaplasia could be a predictive factor. Complete resection is needed to evaluate the whole tumor, because P-EMCs often show histological heterogeneity. Moreover, incomplete excision may be a poor prognostic factor. Although lobectomies as well as lymph node dissections, sleeve lobectomies, or pneumonectomies are routinely performed for complete resection, further investigation is required to establish the optimal treatment strategy.

Adenomyoepithelioma of the breast with late pulmonary metastases - case report and review of the literature

Background

Adenomyoepithelioma (AME) of the breast is a rare tumour of unpredictable clinical behaviour. Most of the tumours are benign with some giving local recurrences or distant metastases.

Case Presentation

We report a case of late lung metastases in a woman with a history of breast adenomyoepithelioma. Partial lobectomy was performed for lung lesions and initial diagnosis was epithelial-myoepithelial carcinoma.

Conclusion

Careful slide’s revision of both breast and pulmonary lesions showed identical microscopic appearance with lung tumour performing more malignant features. Tumour cells in both: breast and pulmonary lesions were positive for cytokeratin and EMA (epithelial cells) and also for SMA, S100 and vimentin (myoepithelial cells). Two years and 7 months follow-up showed no recurrent neoplastic disease in our patient.

A rare case of primary peripheral epithelial myoepithelial carcinoma of lung: Case report and literature review

BACKGROUND

Primary salivary gland-type tumors of lung are rare. Epithelial-myoepithelial carcinoma (EMC) of the lung is a minor salivary gland-type tumor subtype.

METHODS

We report a very rare case of EMC located in the peripheral left lower lobe that was diagnosed in a 58-year-old man and this is the first study in which we summarize all the patients with primary peripheral lung EMC concerned with the clinical features. Informed consent was obtained from the patient.

RESULTS

Chest computed tomography displayed an anomalous soft tissue mass with slightly lobular borders in the peripheral segment of the left lower lobe and closed to the visceral pleura. The surgery was performed by using video-assisted thoracic surgery. Grossly, the tumor was solitary, well-circumscribed, and unencapsulated endobronchial lesion. A microscopic examination revealed that it was circumscribed, although the tumor borders may show single cells or clusters of cells proliferating away from the main tumor mass. The inner tubular layer showed epithelial cell characteristics, whereas the outer layer exhibited myoepithelial cell characteristics. Immunostaining for P40, P63, and cytokeratin 5/6 was positive. However, the anaplastic lymphoma kinase-V, thyroid transcription factor-1, synaptophysin, chromogranin A and napsin A were negative.

CONCLUSIONS

Literature review showed that most of patients with peripheral EMC were asymptomatic. Computed tomography and magnetic resonance imaging scans are able to indicate the presence of peripheral EMC. Pathological analysis is an effective method to clarify the diagnosis. Surgery is a regular treatment method. To facilitate the preoperative diagnosis and avoid the misdiagnosis of such a rare disease, more cases will need to be reported.

Primary Pulmonary Salivary Gland-type Tumors: A Review and Update

Pulmonary salivary gland-type tumors (SGT) comprise a very small proportion of primary lung neoplasms. The most common tumors among this group are mucoepidermoid carcinoma and adenoid cystic carcinoma. Contrary to the head and neck region, benign SGT such as pleomorphic adenomas are exceedingly rare in the pulmonary system. More recently, 2 additional SGT, namely hyalinizing clear cell carcinoma and salivary duct-like carcinoma were recognized as primary lung tumors expanding the spectrum of SGT that have been described to originate in the tracheobronchial system. Primary pulmonary SGT must be clinically excluded from metastatic salivary gland neoplasms as their morphology is indistinguishable from that of their salivary gland counterparts. Little is known about the clinical behavior and best treatment approach for these unusual tumors. In this review, we provide a comprehensive summary of primary pulmonary SGT with particular emphasis on morphologic characteristics and latest developments in terms of immunohistochemical and molecular techniques.

Primary pulmonary myoepithelial carcinoma in a child: An ambiguous entity

Primary myoepithelial carcinoma (MC) of the lung is exceedingly rare. We report here, to the best of our knowledge, the first pediatric case having primitive pulmonary MC. The originality of our case was the disappearance of the pulmonary opacity spontaneously, without any treatment. The difficulties in our case were the diagnosis of this rare entity and its subsequent treatment. In fact, given the rarity of these tumors, recommendations regarding chemotherapy or radiation, were difficult to formulate.

Tracheal epithelial-myoepithelial carcinoma associated with sarcoid-like reaction: A case report

Epithelial-myoepithelial carcinomas are rare tumors that primarily originate in the salivary glands but have also been found in the tracheobronchial tree. We report the first case of epithelial-myoepithelial carcinoma associated with sarcoidosis. A 61 year old Hispanic man presented with altered mental status and hypercalcemia. Imaging revealed diffuse intra-thoracic and intra-abdominal lymphadenopathy. A diagnostic bronchoscopy was performed where an incidental tracheal nodule was discovered and biopsied. Pathology was consistent with epithelial-myoepithelial carcinoma. Lymph node biopsy demonstrated non-caseating granulomas consistent with sarcoidosis. Patient underwent tracheal resection of the primary tumor with primary tracheal reconstruction. Hypercalcemia subsequently normalized with clinical improvement. Repeat CT imaging demonstrated complete resolution of lymphadenopathy. Our findings are suggestive of a possible paraneoplastic sarcoid-like reaction to the epithelial-myoepithelial carcinoma with associated lymphadenopathy and symptomatic hypercalcemia.

Primary salivary gland-type lung cancer: imaging and clinical predictors of outcome

OBJECTIVE

The objective of our study was to assess whether CT features and FDG up-take of primary salivary gland-type tumors of the lung are associated with tumor type, disease stage, or survival.

MATERIALS AND METHODS

CT (n = 30) and PET (n = 15) data of 30 consecutive patients with primary salivary gland-type tumors of the lung were retrospectively evaluated for tumor size, location, and homogeneity and the presence of lymphadenopathy, pleural effusions, and metastases. Maximum FDG uptake and volumetric FDG uptake of the tumors were recorded. The Wilcoxon rank sum and Fisher exact tests and univariate Cox regression were used for statistical calculations.

RESULTS

Compared with mucoepidermoid carcinomas, adenoid cystic carcinomas (57%) were larger (mean, 3.5 vs 2.2 cm, respectively; p = 0.03), more frequently involved the central airways (94% vs 63%; p = 0.002), and had a higher median FDG uptake (p = 0.0264). Higher FDG uptake of the primary tumor was associated with nodal tumor involvement (p = 0.05). The median overall survival times for patients with adenoid cystic carcinoma and mucoepidermoid carcinoma were 7.7 and 4.0 years, respectively. Imaging features that significantly affected overall survival included the presence of mediastinal or hilar lymphadenopathy (hazard ratio [HR], 4.33; 95% CI, 1.15-16.26; p = 0.03), suspected metastatic disease (HR, 5.10; 95% CI, 1.27-20.47; p = 0.02), and primary tumor heterogeneity (HR, 3.46; 95% CI, 1.04-11.55; p = 0.04).

CONCLUSION

Higher FDG uptake is associated with nodal disease in patients with primary salivary gland-type tumors of the lung but is not predictive of survival, whereas CT features suggestive of advanced disease correlate with worse outcome.

Oncocytic and apocrine epithelial myoepithelial carcinoma: novel variants of a challenging tumor

Epithelial myoepithelial carcinoma (EMCa) is a rare but well characterized biphasic salivary gland malignancy with several variant morphologies. Oncocytic and apocrine EMCa are uncommon variants that constitute up to 8 % of all EMCa. Both variants invoke an eosinophilic or oncocytic differential diagnosis and challenge the traditional requirement of clear myoepithelial cells for EMCa. Oncocytic EMCa occurs in patients a decade older than conventional EMCa. This variant is often papillary with calcification and associated with sebaceous components and occurs in older individuals. Apocrine EMCa is named for its apocrine ductal component, which may be mistaken for salivary duct carcinoma. In this variant, the epithelial component often shows overgrowth in a cribriform or even solid pattern and is immunophenotypically defined by androgen receptor and gross cystic disease fluid protein 15 positivity. The most important aspect of differentiating both oncocytic and apocrine EMCa from other salivary oncocytic tumors is recognition of the biphasic nature of these variants and confirmation that the abluminal outer layer consists of plump, 'activated' myoepithelial cells, regardless of tinctorial characteristics. Both oncocytic and apocrine EMCa behave very indolently in the limited literature to date.

Primary epithelial myoepithelial carcinoma of lung, reporting of a rare entity, its molecular histogenesis and review of the literature

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.

Epithelial-myoepithelial tumour of the lung: a case report referring to its molecular histogenesis

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.

Skull metastasis as initial manifestation of pulmonary epithelial-myoepithelial carcinoma: a case report of an unusual case

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.

Primary myoepithelial carcinoma of the lung: a rare entity treated with parenchymal sparing resection

Primary lung myoepithelial carcinomas are rare neoplasms arising from the salivary glands of the respiratory epithelium. Given the rare occurrences and reports of these tumors, appropriate recommendations for resection are difficult to formulate. Although classified as low-grade neoplasms, these tumors have a significant rate of recurrence and distant metastasis.

Primary adenomyoepithelioma of tonsil

We present a case of adenomyoepithlioma (AME) arising from the tonsil. AME is an uncommon tumor that typically arises in breast, but rarely found in salivary glands, lung, and skin. Its biological features have not been thoroughly characterized. Here we describe a primary AME originating from the tonsil. The pathologic changes were characterized by hypercellularity, the dominance of both epithelial and myoepithelial cells. Malignancy was evidenced by the presence of a high mitotic rate and invasive growth. The epithelial cells express high levels of cytokeratin and epithelial membrane antigen (EMA). The myoepithelial cells show positive staining for calponin, p63, vimentin, and S-100. A thorough review of the literature indicates that this is likely the first reported case of AME from the tonsil. Following descriptions of the diagnosis, treatment, and prognosis of this specific case, pathologic and clinical characteristics of AME from other tissues are also compiled and discussed.

Pneumocytic Adenomyoepithelioma: A Distinctive Lung Tumor With Epithelial, Myoepithelial, and Pneumocytic Differentiation

Pulmonary tumors with epithelial and myoepithelial differentiation are rare, thought to be of bronchial minor salivary gland origin and classified similarly to salivary gland neoplasms. We report a series of a distinctive subtype of pulmonary glandular tumors showing epithelial and myoepithelial differentiation with further pneumocytic specialization. All patients were women, aged 52 to 63 years and presented with single or multiple pulmonary nodules. The tumors were grossly circumscribed, 0.8 to 2.6 cm in greatest dimension, and histologically showed glandular and spindle cell differentiation. Some glands were filled with colloidlike secretion and had an inner, cuboidal epithelial cell layer (pankeratin, epithelial membrane antigen, and thyroid transcription factor-1 positive), surrounded by an outer layer of myoepithelial cells merging with foci of spindled myoepithelial cells (high molecular weight keratin, S100, smooth muscle actin, calponin, caldesmon, and p63 positive). There were also some glands lined by a single layer of plump cells that were positive for surfactant protein-A in addition to the other epithelial cell markers. Electron microscopy confirmed pneumocytic features in these cells and the myoepithelial nature of the spindled cells. The surgery in all cases was wedge resection of the masses. The biologic behavior to date has been benign. This is the first reported series of a distinctive lung tumor with epithelial, myoepithelial, and pneumocytic differentiation that differs histologically from all previously recognized pulmonary salivary gland-type and pneumocytic tumors. It is a unique benign appearing neoplasm for which the designation pneumocytic adenomyoepithelioma is suggested.

Epithelial-myoepithelial carcinoma: a review of the clinicopathologic spectrum and immunophenotypic characteristics in 61 tumors of the salivary glands and upper aerodigestive tract

To further define the clinicopathologic spectrum of epithelial-myoepithelial carcinoma (EMCa), we report the gross, histologic, and immunophenotypic characteristics of 61 tumors seen within a 30-year-period. The mean age at presentation was 60.9 years, with a female predominance (1.5:1). The most common sites were parotid (62.1%), sinonasal mucoserous glands (10.3%), palate (8.6%), and submandibular (8.6%). Most EMCas showed a characteristic nodular/multinodular growth pattern and classic biphasic tubular histology. However, new morphologies in EMCa such as ancient change (8.2%), "Verocay"-like change (3.3%), and sebaceous differentiation (13.1%) were noted. Specific histologic variants were dedifferentiated EMCa (3.3%), oncocytic EMCa (8.2%), EMCa ex pleomorphic adenoma (1.6%), double-clear EMCa (3.3%), and EMCa with myoepithelial anaplasia (3.3%). All cytokeratin cocktails selectively highlighted the epithelial component well. Of the myoepithelial markers, p63, smooth muscle actin and vimentin performed best. Bcl-2 and c-kit were frequently positive (66.7% and 69.2%, respectively). p53 was highly expressed only in 1 dedifferentiated EMCa. The recurrence rate was 36.3% (median disease-free survival 11.34 y), but death was rare with 5-year and 10-year disease-specific survivals of 93.5% and 81.8%, respectively. The most important univariate predictors of recurrence were margin status (log rank P=0.006), angiolymphatic invasion (P=0.002), tumor necrosis (P=0.004), and myoepithelial anaplasia (P=0.038). Thus, EMCa is generally a low-grade tumor with a broader morphologic spectrum than previously thought, with several key features predictive of recurrence. Immunohistochemistry can aid diagnosis by highlighting the biphasic nature of the tumor.

Bronchial Epithelial-Myoepithelial Carcinoma

Epithelial-myoepithelial tumor is extremely rare as a pulmonary neoplasm. Only 20 cases have been reported to date, of which 14 were malignant. We report a case of intrabronchial epithelial-myoepithelial carcinoma in a 73-year-old man with a history of heavy smoking. The tumor was well-circumscribed and caused distal airway obstruction. Histologically, the tumor showed glandular and solid architecture. The glands were composed of an inner layer of epithelial cells and an outer layer of myoepithelial cells. The solid areas consisted of spindle-shaped myoepithelial cells. Immunohistochemical staining was positive for p53 and c-Kit (CD117). Focal atypia and increased mitotic activity were present, but no vascular invasion or nodal metastasis was identified.