Myoepithelial carcinoma of the lung arising from bronchial submucosa

Rare but clinically important salivary gland-type tumor of the lung: A review

Salivary gland-type tumor (SGT) of the lung, which arises from the bronchial glands of the tracheobronchial tree, was first recognized in the 1950s. SGT represents less than 1% of all lung tumors and is generally reported to have a good prognosis. Mucoepidermoid carcinoma (MEC) and adenoid cystic carcinoma (ACC) are the two most common subtypes, comprising more than 90% of all SGTs. The reported 5-year survival rate of patients with SGT is 63.4%. Because this type of tumor develops in major bronchi, patients with SGT commonly present with symptoms of bronchial obstruction, including dyspnea, shortness of breath, wheezing, and coughing; thus, the tumor is usually identified at an early stage. Most patients are treated by lobectomy and pneumonectomy, but bronchoplasty or tracheoplasty is often needed to preserve respiratory function. Lymphadenectomy in the surgical resection of SGT is recommended, given that clinical benefit from lymphadenectomy has been reported in patients with MEC. For advanced tumors, appropriate therapy should be considered according to the subtype because of the varying clinicopathologic features. MEC, but not ACC, is less likely to be treated with radiation therapy because of its low response rate. Although previous researchers have learned much from studying SGT over the years, the diagnosis and treatment of SGT remains a complex and challenging problem for thoracic surgeons. In this article, we review the diagnosis, prognosis, and treatment (surgery, chemotherapy, and radiotherapy) of SGT, mainly focusing on MEC and ACC. We also summarize reports of adjuvant and definitive radiation therapy for ACC in the literature.

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.

Primary high-grade myoepithelial carcinoma of the lung: A study of three cases illustrating frequent SMARCB1-deficiency and review of the literature

Primary myoepithelial carcinoma of the lung is exceptionally rare and, hence, remained poorly characterized. We present 3 tumors affecting 2 males and 1 female aged 60 to 84 years. Tumor size ranged from 4 to 10 cm. All presented as well circumscribed non-encapsulated peripheral solitary masses. One patient died postoperatively. The other two were lost to follow-up. Histologically, all tumors were high-grade with predominance of myxoid/chordoid (2) and rhabdoid (1) pattern. Immunohistochemistry (IHC) showed reactivity with vimentin, pankeratin, EMA and smooth muscle actin. Two tumors were SMARCB1-deficient (one with additional loss of SMARCA2 and PBRM1). RNA sequencing revealed no gene fusions. Review of reported cases (total: 16) showed that pulmonary myoepithelial carcinoma affects both sexes equally at a median age of 60 years (24-84), presents predominantly as peripheral masses (69%) in the lower lobes (66%) of smokers (70%) with a median size of 6 cm (1.5-13), and originates as high-grade de novo carcinoma. Forty percent of patients died of disease at a median of 12.5 months (0 to 62). Only 40% of patients were disease free at last follow-up (median, 9.5 months). Prominent lobulation and myxoid stroma were frequent histological features. Most tumors displayed variable combinations of epithelioid, spindle, plasmacytoid, clear, ovoid or round cells. Three of 6 tumors subjected to different RNA panels showed EWSR1 rearrangements (fused to PBX1, ZNF444 or to unknown partner). Two of 3 tumors lacking gene fusions were SMARCB1-deficient (both showed secondary EWSR1 FISH abnormalities due to 22q deletion). Primary pulmonary myoepithelial carcinoma is a rare aggressive malignancy that recapitulates its soft tissue and salivary counterpart. Exclusion of metastasis from other primaries is mandatory and can only be achieved by detailed clinical history and imaging.

A first case report of clinical response to targeted therapy in a patient with primary myoepithelial carcinoma of the lung harboring EGFR exon 19 deletion

BACKGROUND

Primary myoepithelial carcinoma of the lung is a rare subtype in lung cancer. Comprehensive molecular profiling of myoepithelial carcinoma of the lung is absent, neither was clinical evidence of targeted therapy available for this disease. Therefore, the optimal treatment regimen of this tumor needs to be established.

CASE PRESENTATION

Here we present a case of a 68-year-old patient with stage IVB primary myoepithelial carcinoma of the lung who harbored EGFR exon 19 deletion and KRAS mutation and underwent icotinib targeted therapy, achieving partial response (PR) with progression free survival (PFS) of 3 months.

CONCLUSION

To our knowledge, this study describes the first documented case of primary myoepithelial carcinoma lung cancer patient harboring EGFR exon 19 deletion and KRAS mutation, and showed clinical efficacy of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKI) treatment in this patient.

Primary pulmonary myoepithelial carcinoma in a young woman: A case report and review of literature

RATIONALE

Myoepithelial carcinoma mainly occurs in the salivary glands, but myoepithelial carcinoma of the lung is extremely rare neoplasm whose biological behavior and clinical course still remain to be fully elucidated. Although considered as low-grade carcinoma, these tumors have a high rate of recurrence or distant metastasis.

PATIENT CONCERNS

To date there are only 11 cases of pulmonary myoepithelial carcinoma reported in the English literature. We report a case of a 24-year-old woman diagnosed with primary pulmonary myoepithelial carcinoma. Informed consent was obtained from the patient.

DIAGNOSES

The tumor derived from superior lobe of left lung and exhibited only myoepithelial differentiation without any ductal formation by histopathological and immunohistochemical analysis.

INTERVENTIONS

The patient underwent the left superior lobe resection. In addition, we first introduce second-generation sequencing technology as a novel strategy for primary pulmonary myoepithelial carcinoma, and these tumors should be included in the differential diagnosis of thoracic neoplasms.

OUTCOMES

The patient was alive with no evidence of disease for up to 12 months.

LESSONS

Individualized treatment is the promising clinical strategy for thoracic neoplasms, and the underlying molecular events should be investigated to find the potential therapeutic targets.

A rare large cutaneous chondroid syringoma involving a toe: A case report

RATIONALE

Chondroid syringoma (CS) occurs mostly on the face and neck, and rarely occurs in the toe. Malignant CS is invasive, grows quickly, and has a high recurrence rate. The presence of a bilobed CS in 1 toe has never been reported in the literature.

PATIENT CONCERNS

A 72-year-old male patient presented with a mass in a third toe of his right foot. The mass had slowly grown in 2 years. He felt mild pain and the mass occupied most of the tip of the toe.

DIAGNOSES

Radiographs showed a large soft-tissue mass in the third toe of his right foot without any bone destruction. Ultrasonogram showed 2 partly fused hypoechoic masses within the lesion. The mass was therefore diagnosed as a benign CS.

INTERVENTIONS

We amputated the toe with the mass under local anesthesia. The postoperative pathohistological examinations confirmed that the lesion was a bipartite CS exhibiting active cellular proliferation.

OUTCOMES

Two years after surgery, there was no tumor recurrence.

LESSONS

CS can also present as multiple adjacent masses. Complete surgical resection and long-term follow-up are essential.

Primary Pulmonary Myxoid Sarcoma: A Newly Described Entity-Report of a Case and Review of the Literature

Primary pulmonary myxoid sarcoma (PPMS) is a recently described, exceedingly rare low-grade lung sarcoma that tends to present in young females as an endobronchial mass and shows evidence of an EWSR1- CREB1 fusion. Herein, we present a case of PPMS with fluorescence in situ hybridization (FISH) analysis for EWSR1 and CREB1 rearrangements. An 80-year-old woman presented with an endobronchial, multinodular tumor exhibiting spindle, ovoid and epithelioid cells arranged in reticular/lattice-like and alveolar-like patterns in a myxoid background. The tumor showed focal epithelial membrane antigen immunoreactivity as well as an Alcian blue-positive stroma that was sensitive to digestion with hyaluronidase. EWSR1 and CREB1 rearrangements were detected by break-apart FISH probes. The patient showed persistence of disease 36 months after diagnosis and was discharged to hospice care. We contribute with a report of an additional case of this very unusual entity and perform a brief review of the literature published so far on the subject.

Myoepithelial carcinoma with RB1 mutation: remarkable chemosensitivity to carcinoma of unknown origin therapy

Background

Myoepithelial carcinoma of soft tissue is a rare, malignant neoplasm that is morphologically and immunophenotypically similar to its counterpart in salivary gland. It demonstrates myoepithelial differentiation, possessing both epithelial and myogenic characteristics. Thought to be chemotherapy insensitive, the optimal treatment regimen of this tumor has yet to be established and only a select few cases in the literature discuss treatment efficacy in detail.

Case presentation

Here we present a case of a young adult with metastatic myoepithelial carcinoma with an initial excellent response to systemic therapy utilizing carboplatin and paclitaxel with continued complete response after 3 years. The patient also underwent complete surgical excision and received adjuvant radiation to the primary site of disease. Exome sequencing revealed an inactivating mutation in RB1 which we believe to be the first such mutation to be reported in this cancer type.

Conclusions

Given increasing evidence suggesting RB1 loss is associated with responsiveness to conventional chemotherapies, particularly platinum-based regimens, we hypothesize that this genetic feature predisposed chemosensitivity in our patient’s tumor.

Thoracic Myoepithelial Tumors: A Pathologic and Molecular Study of 8 Cases With Review of the Literature

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/2 mm² (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, fusion-positive 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/2 mm²/10 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.

Primary pulmonary myxoid sarcomas with EWSR1-CREB1 translocation might originate from primitive peribronchial mesenchymal cells undergoing (myo)fibroblastic differentiation

Primary pulmonary myxoid sarcoma (PPMS) is a very rare lung tumor that has recently been shown to harbor an EWSR1-CREB1 translocation. However, the histogenesis and biological behavior of PPMS remains unclear. To provide insight into the histogenesis of PPMS, we studied surgical resection specimens of four patients, two females and two males with an age range of 26 to 65 years, all non-smokers with mild anemia. The tumors, three of which are endobronchial, measured between 4 and 13 cm. One patient developed metastasis to the contra-lateral lung 7 months after resection. Other patients remained alive without tumor for 1.5, 10, and 13 years. Fluorescence in situ hybridization (FISH) analysis with a gene break apart probe showed an EWSR1 translocation in all cases. The EWSR1-CREB1 fusion transcript was detected in all cases by reverse-transcription PCR. Immunohistochemical staining showed diffuse positive staining of the tumor cells only for vimentin. Tumor cells expressed no other myoid, epithelial, endothelial, melanocytic, myoepithelial, or neuroendocrine markers, except for smooth muscle actin and epithelial membrane antigen, which were only focally positive in individual cases. Ultrastructural analyses revealed the presence in the tumor cells of intermediate filaments with focal densities along the sub-cytoplasmic membrane as well as dense plaques. These results suggest that PPMS exhibits myofibroblastic differentiation. We conclude that PPMS is an intermediate grade malignant lung tumor harboring EWSR1 translocations, which may originate from mesenchymal cells that undergo fibroblastic or myofibroblastic differentiation.

Myoepithelioma of the Orbital Apex and Middle Cranial Fossa: Case Report and Review of the Literature

Myoepitheliomas are rare tumours that originate from glandular tissues such as the parotid or salivary glands, and less commonly from soft tissues of the head, neck, and other parts of the body. Intraorbital myoepitheliomas generally arise from the lacrimal gland. Intracranial myoepitheliomas are rare. We report a myoepithelioma of the orbital apex that did not originate from the lacrimal gland. It extended to the middle cranial fossa from the orbital apex and involved the dura and adjacent bone. A diagnostic biopsy via a lateral orbitotomy preceded resection. We review the natural course and histopathology of myoepithelial neoplasms, the surgical nuances of approaching an orbital apex tumour with maximal functional preservation, and the optimal management practices of these rare lesions.

Incidence of pulmonary non-epithelial tumors: 18 years' experience at a single institute

Primary and metastatic non-epithelial tumors of the lung and pleura (NETs-LP) are presumed to represent a small proportion of pulmonary neoplasm, and their epidemiologic characterization is lacking. Moreover, classification of pulmonary mesenchymal tumor according to 'WHO Classification of Tumors of Lung and Pleura' (2004) is simple and necessary to give a supplementation like new 'WHO Classification of Tumors of Soft Tissue and Bone' (2013). Non-epithelial tumors of the lung and pleura diagnosed from January 1995 to April 2013 were retrospectively reviewed and classified in accordance with 'WHO Classification of Tumors of Soft Tissue and Bone' (2013). Of 681 cases represented in the study, smooth muscle tumor (13.1%) was most common, and tumor of uncertain differentiation (10.5%) and fibroblastic/myofibroblastic tumor (5.7%) were followed. Smooth muscle tumor (12.6%) was the common primary tumor, whereas chondrogenic or osteogenic tumor (21.6%) was common in metastatic ones. Pulmonary vascular sarcoma (n=15) was the most frequent primary pulmonary sarcoma with following synovial sarcoma (n=9) and malignant type of solitary fibrous tumor (n=9). This study is the first trial of epidemiologic investigation in Korea about NETs-LP, indirectly representing their incidence in Korea and northeast Asia, and we hope that this presentation offers guidance in further study of NETs-LP.

Rapid-developed primary malignant myoepithelioma in the cavernous sinus: a case report

Background

Malignant myoepithelioma is a relatively rare malignant tumor occurring most frequently in the salivary glands. A few isolated cases have been described in other locations, including soft tissue, bone, lung, bronchus, oral cavity, nasopharynx, larynx, and maxillary sinus. Malignant myoepithelioma, however, is uncommonly involved within the cavernous sinus. To the best of our knowledge, this is the first report of malignant myoepithelioma arising from within the cavernous sinus.

Case presentation

Herein, we report a case of a 48-year-old woman who presented a 1-month history of diplopia and blepharoptosis as well as radiological evidence of a rapidly developing cavernous sinus tumor. The patient underwent a trans-sphenoidal biopsy and a histological diagnosis indicated a malignant myoepithelioma. After diagnosis, the tumor grew rapidly and her clinical condition deteriorated progressively. Therefore, a pterional craniotomy with partial tumor removal was performed. The patient’s clinical state was worsened, and she died two months after the initial operation. Because the malignant myoepithelioma could not be traced to an organ of origin, other than the cavernous sinus, this case was diagnosed as a primary intracranial malignant myoepithelioma.

Conclusion

The purpose of presenting this case report is to raise awareness among clinicians to consider malignant myoepithelioma as a differential diagnosis when a cavernous sinus mass is identified. Furthermore, an ideal management strategy for malignant myoepithelioma is not known and the prognosis seems to be unfavorable; therefore, more cases are needed to enhance our knowledge of the diagnosis, treatment, and prognosis of this rare intracranial lesion.

Unusual myoid, perivascular, and postradiation lesions, with emphasis on atypical vascular lesion, postradiation cutaneous angiosarcoma, myoepithelial tumors, myopericytoma, and perivascular epithelioid cell tumor

In recent years, a number of new soft tissue tumor entities have been described that occur in the skin only, or that also occur in other sites but form clinically and pathologically distinct subsets when arising in the skin and subcutaneous tissue. These include a variety of mesenchymal lineages and have variable malignant potential, although superficial malignant soft tissue tumors generally have a more favorable outcome than their more deeply located counterparts. This article reviews the clinical and pathologic features and differential diagnoses of atypical vascular lesion, postradiation cutaneous angiosarcoma, myoepithelioma, myopericytoma, and perivascular epithelioid cell tumor.

Myoepithelial carcinoma: first case reported in the trachea

Myoepithelial carcinoma displaying exclusively myoepithelial differentiation mainly occurs in the salivary glands and breasts, and is considered extremely rare in the trachea. We present the first documented case of a primary myoepithelial carcinoma in the trachea. The patient was a 23-year-old man who presented with shortness of breath and cough for four months. Bronchoscopy and computed tomographic (CT) scan revealed an intraluminal mass in the trachea. A standard sleeve of trachea resection with end-to-end reconstruction was performed. The tumor was mainly composed of spindle cells and epithelioid cells which exhibited relatively uniform nuclei with finely distributed chromatin and inconspicuous nucleoli, suggesting that it may arise from benign myoepithelioma. Moreover, the tumor displayed marked cytologic atypia and an infiltrative tumor border in some areas, suggesting that it was a malignant tumor. Immunohistochemically, the tumor cells were diffusely positive for AE1/AE3, Vimentin and myoepithelial makers (Calponin, P63 and GFAP). The patient's postoperative course was uneventful with no evidence of recurrence at six months after surgery.

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.

Benign myoepithelioma of the lung - a case report and review of the literature

Introduction

Benign myoepithelioma is extremely rare in the lung, to the best of our knowledge; only five cases have been reported in the literature.

Case Report

An 18-years woman complained from tiredness and fever during four months. Laboratory findings and fibroscopies were normal. CT of the thorax demonstrated a nodule in the left segment of the Fowler. Left inferior lobectomy was performed comporting a firm nodule of 25 mm, lifting the bronchial mucous membrane. Histologically, there was a proliferation of small cells of a plasmocytoid-type, with a predominantly whorled pattern. No mitotic activity or necrosis was seen in the tumor. Immuhistochemically, the tumor cells positive for smooth muscle actin, vimentine, and S100 protein. They were negatives for cytokeratine, chromogranine and HMB45. The diagnosis of benign myoepithelioma of the lung is so confirmed. The patient recovered well at 6 months follow-up.

Conclusion

Benign myoepithelioma is a rare pulmonary neoplasm distinct from pleomorphic adenoma, which should be considered in the differential diagnosis of lung nodules.

Salivary Gland Myoepithelioma with Focal Capsular Invasion

Salivary gland tumors that display myoepithelial differentiation exclusively or predominantly are relatively uncommon, and the assessment of malignancy in a myoepithelial tumor can be difficult. We report a case of parotid gland myoepithelioma composed predominantly of spindle cells with focal capsular invasion. The patient was a 65-year-old woman who presented with a painless mass in the right preauricular region. Histologically, the tumor had a solid and multinodular growth pattern and was predominantly made up of spindle cells with a minor component of epithelioid cells with moderate cellular atypia. Focal regions of tumor cells infiltrated the capsule with tongue-like processes, hut tumor infiltration into the adjacent parotid tissue was absent. The tumor cells showed strong cytoplasmic immunoexpression of vimentin, pankeratin, S-100 protein, and smooth-muscle actin. Immunostains with glial fibrillary acidic protein, melanoma marker, epithelial membrane antigen, and carcinoembryonic antigen were negative. Expression of p53 was observed focally in the nuclei of the tumor cells. A final diagnosis of salivary gland myoepithelioma with focal capsular invasion was made, and the case was regarded as a myoepithelial tumor of uncertain malignant potential. In this report, we discuss the histologic criteria required to diagnose malignancy in salivary gland myoepithelial tumors.

A case of cutaneous myoepithelial carcinoma

BACKGROUND

Cutaneous myoepithelioma, both benign and malignant, is a rare neoplasm composed of neoplastic myoepithelial cells showing diverse histopathological features, and criteria for discriminating benign or malignant have not been fully clarified.

PATIENT

We present a case of cutaneous myoepithelial carcinoma in a 62-year-old woman presenting a solid mass in the right back.

RESULTS

Resected tumor was located in the whole dermis and subcutis. Histopathologically, two different growth patterns were noted: a small-nested or trabecular pattern in the superficial part and a large nodular pattern with extensive central necrosis in the deep part. Tumor cells were all epithelioid, although plasmacytoid and glycogen-rich clear cells were also observed within the large nodules of the deep part. Immunohistochemically, the cells were positive for both epithelial and myogenic markers, suggesting myoepithelial origin. Lymphatic invasion and lymph node metastasis were evident despite inconspicuous atypia and low mitotic rate.

CONCLUSION

The final diagnosis was cutaneous myoepithelial carcinoma. At present, it seems to be difficult to predict the behavior of myoepithelioma of the skin and soft tissue, although atypia and high mitotic rate are reported to be associated with local recurrence and metastasis.

Malignant myoepithelial tumor of soft tissue: a report of two cases of the lower extremity and a review of the literature

Myoepithelial tumors of the soft tissues have only recently been described. Two cases of lower extremity malignant myoepithelial tumors are reported. One case of malignant mixed tumor overlying the gastrocnemius muscle was treated with wide local excision, but metastasized to regional lymph nodes 14 months after surgical excision. One patient with malignant myoepithelioma of the right lower leg was treated with limb amputation and is alive without disease at 46 months. A review of the literature discloses 120 additional cases of soft tissue myoepithelial tumors, 102 of which are myoepitheliomas and 18 are mixed tumors. Thirty-seven percent of the myoepitheliomas met the criteria for malignancy, and 33% of the mixed tumors were malignant. Of these, 30% had locally recurrent disease and 32% developed metastatic disease. Treatment benefit from chemotherapy and radiation therapy is unclear.

Solid type clear cell carcinoma of the pancreas: differential diagnosis of an unusual case and review of the literature

Pancreatic neoplasms have been reliably classified on the basis of their histopathology and immunophenotype. In this study, we report on a pancreatic tumor whose phenotype and genotype could not be assigned to any known tumor entity. The tumor was observed in the pancreatic head of a 54-year-old woman. It was found to be a solid infiltrating carcinoma with abundant clear cells. Apart from cytokeratin, the tumor cells expressed vimentin, S100, and MUC-1. DNA microarray analysis revealed a transcription profile clearly differing from that of normal pancreatic tissue and pancreatic ductal adenocarcinoma. Despite metastatic behavior, the tumor displayed a more favorable course than conventional pancreatic ductal adenocarcinoma. We suggest that this tumor be called solid type clear cell carcinoma of the pancreas.

Bronchial epithelial-myoepithelial carcinoma

An epithelial-myoepithelial tumor is an extremely rare pulmonary neoplasm. Only 21 cases have been reported to date. This report presents a case of left main bronchial epithelial-myoepithelial carcinoma in a 43-year-old woman. No mediastinal lymph nodes were enlarged in computed tomographic scan, and no tumor growth was noted beyond the bronchial cartilage layer by endobronchial ultrasound imaging. This report highlights the usefulness of endobronchial ultrasound imaging for determining the depth of tumor invasion and choosing an alternative approach to surgical resection.

[Benign myoepithelioma of the lung]

Benign myoepithelioma of the lung is a benign tumor caused by proliferating myoepithelial cells with no ductal component. These tumors are exceptional: only three cases have been reported in the literature. We report a fourth case in a 37-year-old woman at 8 months gestation. Pathological proof of diagnosis was obtained.

Malignant myoepithelioma. Clinicopathological and immunohistochemical characteristics

A malignant myoepithelioma arising in the submucosal accessory glands of the oral cavity of a 23-year-old woman is reported. The patient was very young compared to the cases in the literature, and the tumour had an unusual vestibular location. A false diagnosis of pleomorphic adenoma had been made by fine needle aspiration biopsy. The surgery comprised a wide tumour excision, but neck dissection was not indicated. The final histologic diagnosis was malignant myoepithelioma. Immunohistochemically putative myoepithelial markers were highly expressed.

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

Primary lung tumors mimicking the salivary gland-type neoplasms are extremely rare. These types of tumors originate from submucosal bronchial glands. Epithelial-myoepithelial carcinoma is an uncommon tumor in this group, and only 7 cases have been reported. It is considered to be a low-grade malignant neoplasm. We report a case of epithelial-myoepithelial carcinoma of bronchial gland origin in a 73-year-old man who presented with coughing and dyspnea. The bronchus of the left lower lobe contained a tumor mass that had a polypoid growth pattern. The tumor also extended into the pulmonary parenchyma, forming a well-circumscribed mass with a pushing margin. The tumor consisted of epithelial and myoepithelial cells. The epithelial cells were positive for cytokeratins and epithelial membrane antigen, while the myoepithelial cells were positive for S100 protein and muscle-specific actin. According to these findings, we diagnosed epithelial-myoepithelial carcinoma. After undergoing pneumonectomy, the patient has been disease free for 34 months.

Epithelial-myoepithelial carcinomas of the bronchus

Epithelial-myoepithelial carcinomas are very rare in the lung, and little is known about the relationship of their histologic features to prognosis. We describe five primary pulmonary epithelial-myoepithelial carcinomas with details on clinical presentation, histology, and immunohistochemical profiles. We also reviewed the literature to detail further their prognosis. The patients' ages ranged from 33 to 57 years (average 51 years). The tumors were all endobronchial and the patients presented with symptoms or imaging features of airway obstruction. The tumors were completely resected; none showed nodal involvement. All five patients are alive and free of disease 4 months to 8 years (average 4.2 years) after surgery. Four tumors showed a mixed pattern of glands lined by a dual layer of cells and solid sheets of either spindle cells or clear cells, the glandular and solid components being present in variable proportions. The fifth tumor comprised purely spindle cells. The mitotic rate was <1/20 high power fields in both the glandular and spindle/clear cell components. In one case there was focal nuclear pleomorphism. The inner layer of the glands stained for cytokeratins and epithelial membrane antigen, and the outer layer for S-100 and smooth muscle actin. In one case the spindle cells stained for CD34. A review of published cases shows the majority of tumors behave in an indolent fashion, the rare aggressive tumors being predominantly myoepitheliomatous. Nevertheless, the term epithelial-myoepithelial carcinoma is preferred because of their malignant potential. A high mitotic rate, tumoral necrosis, and nuclear pleomorphism appear to be adverse prognostic factors.

Benign myoepithelioma of the lung: a case report and review of the literature

This report describes a benign myoepithelioma of the lung that occurred in a 60-year-old woman. The patient had experienced hoarseness for 6 weeks, and a computed tomographic scan showed a nodule of approximately 2 cm in diameter at the peripheral portion of her right upper lung. Positron emission tomography showed no uptake of F-18 fluorodeoxyglucose in the nodule. Wedge biopsy of the lesion showed benign spindle cells arranged in a whorled pattern. The cells were positive for both cytokeratin and smooth muscle actin, which corresponded to the presence of tonofilaments and myofilaments that were identified ultrastructurally. The features of the present case of benign myoepithelioma that differ from features of previously reported benign and malignant cases of myoepithelioma in the lung are discussed in the report.