Pulmonary Epithelial-myoepithelial Carcinoma Research Articles

Pulmonary Epithelial Myoepithelial Carcinoma on 18F-FDG PET/CT

Abstract Pulmonary epithelial myoepithelial carcinoma is very rare. We reported the imaging finding of pulmonary epithelial myoepithelial carcinoma of bronchus in a 61-year-old man on 18F-FDG PET/CT. An irregular mass with an SUVmax of 6.36 growing along right upper lobe bronchus and multiple pulmonary nodules around the mass were found on 18F-FDG PET/CT. Postoperative pathology demonstrated the diagnosis of epithelial myoepithelial carcinoma.

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.

A Rare Case of Pulmonary Epithelial-myoepithelial Carcinoma: Case Report and Literature Review

背景与目的肺上皮-肌上皮癌（pulmonary epithelial-myoepithelial carcinoma, P-EMC）是一种十分罕见的涎腺型肺肿瘤，尚无标准治疗方案，本文拟分析肺上皮-肌上皮癌的临床特点，探讨肺上皮-肌上皮癌的诊疗方案。方法分析1例肺上皮-肌上皮癌患者的临床资料并回顾其他相关临床文献。结果上皮细胞免疫组化表达细胞角蛋白，肌上皮细胞免疫组化表达SMA及S-100，二代基因测序以HRAS基因突变为主，PD-L1蛋白为阴性。结论肺上皮-肌上皮癌大多预后良好，诊断以镜检及免疫组化为主，治疗以手术切除为主，放化疗效果尚不明确。

Primary epithelial-myoepithelial carcinoma of�the�lung with cavitary lesion: A case report

Epithelial-myoepithelial carcinoma (EMC) typically arises in the salivary glands, whereas EMC of the lung is an extremely rare histological form that originates from the bronchial glands. Although cavitation in primary lung cancer is not uncommon, to the best of our knowledge, a case of EMC with a cavitary lesion has not been reported to date. We herein describe a case of cavity-forming pulmonary EMC. A 72-year-old man was referred to our department due to a thickened cystic wall discovered in the upper lobe of the left lung and underwent thoracoscopic left upper lobectomy. Microscopically, the tumor was characterized by biphasic architecture, with glands surrounded by myoepithelial cells. The pathological diagnosis was EMC. The patient has remained in good health for 2 years postoperatively, without any evidence of recurrence. As regards the mechanism of cavity formation, it was hypothesized that the bronchial gland in the primary cystic lesion had been present 3 years prior to the development of the EMC, and grew to become a cavitary lesion. Therefore, although the mechanism of cavity formation remains to be elucidated, EMC of the lung may include a cavitary lesion.

肺原発上皮筋上皮癌の一切除例

58歳，男性．健診の胸部Xpにて左下肺野に結節影を指摘された．胸部CTにて左S8に20 mm大の充実性陰影を認めた．気管支鏡ではB8b入口部に表面平滑な腫瘤を視認でき，同部からの生検では唾液腺型の腫瘍と診断された．手術は胸腔鏡下左下葉切除術を行った．切除標本では，腫瘍径は27×18 mm，境界明瞭，白色充実性で気管支壁に浸潤し，一部は内腔へ突出していた．組織学的には，淡明な胞体をもつ異型細胞が，小管状構造，胞巣状構造を密に形成し，周囲圧排性に増殖していた．管腔内腔には好酸性の腺上皮も見られ，筋上皮・腺上皮の2相性の増殖が確認された．免疫染色では，多くの腺上皮でサイトケラチンAE1/AE3が陽性，多くの筋上皮でp63陽性，一部の筋上皮でSMAおよびS-100陽性であった．以上から上皮筋上皮癌と診断された．術後経過は良好で，術後第14病日に退院した．術後1年が経過したが再発は認めていない．

P1.02-025 A Case of Primary Peripheral Epithelial–Myoepithelial Carcinoma of the Lung

Primary epithelial-myoepithelial carcinoma (EMC) of the lung is extremely rare carcinoma of salivary type lung cancer. Only 16 cases were reported for peripheral pulmonary EMC in literatures in the world, at present.

First case report of a curative wedge resection in epithelial–myoepithelial carcinoma of the lung

Epithelial-myoepithelial carcinoma is a well differentiated malignant neoplasm, which originates from the salivary glands. The primary pulmonary manifestation is rare-about 30 cases have been reported worldwide. In the literature, anatomical resection has been described as the standard surgical approach. In the presented case, a wedge resection was performed, with no evidence for tumor relapse in the follow-up reevaluation after 24months. This is the first case report of a primary pulmonary epithelial-myoepithelial carcinoma that has been treated with a non-anatomical wedge resection and lymph node dissection as a curative approach.

A Rare Case of Bronchial Epithelial-Myoepithelial Carcinoma with Solid Lobular Growth in a 53-Year-Old Woman.

Epithelial-myoepithelial carcinoma (EMC) of lung is a minor subset of salivary type carcinoma of lung of known low grade malignancy. Histologically, two-cell components forming duct-like structure with inner epithelial cell layer and outer myoepithelial cell layer are characteristics of EMC. In salivary gland, dedifferentiation of conventional low grade malignancy has been reported and is thought to be related with poor prognosis. However, precise histomorphology and prognostic factors of pulmonary EMC have not been clarified due to its rarity. Herein, we reported a rare case of EMC presented as endobronchial mass in a 53-year old woman, which showed predominant solid lobular growth pattern and lymph node metastases.

Primary Epithelial Myoepithelial Lung Carcinoma

Primary epithelial-myoepithelial carcinoma (EMC) of the lung is an extremely rare neoplasm that originates from submucosal bronchial glands and has been found in the salivary glands, breast tissue, and sweat glands. However, only a few cases in the respiratory tract have been identified. In the literature, most pulmonary EMCs have been reported to have developed endobronchially although a few EMC cases have been presented as intraparenchymatous tumors. We have identified a case of primary EMC that developed in the peripheral lung parenchyma.

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.

CASE REPORT: Epithelial-myoepithelial carcinoma of the bronchus

Pulmonary epithelial-myoepithelial carcinoma is a rare low-grade malignant neoplasm that has the characteristic histologic features, epithelial and myoepithelial differentiation, similar to the salivary gland counterpart. This tumor is thought to arise from bronchial submucosal glands distributed throughout the lower respiratory tract. We recently experienced a case of epithelial-myoepithelial carcinoma of the bronchus in a 61-year-old man. Computed tomography of his chest revealed an endobronchial mass in the bronchus of the left lower lobe. The lobectomy specimen showed a solitary endobronchial mass, measuring 2.3 cm in greatest diameter. Histologically, the tumor was composed of variable proportions of epithelial and myoepithelial cells. The epithelial cells represented an inner layer of duct-like structures and the outer clear cell layer was myoepithelial-type cells. The epithelial cells were positive for pancytokeratin and the clear myoepithelial cells were positive for vimentin, alpha-smooth muscle actin and S-100 protein. Finally our diagnosis was epithelial-myoepithelial carcinoma of the bronchus.

Pulmonary epithelial-myoepithelial carcinoma: a clinicopathologic and immunohistochemical study of 5 cases

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.

肺上皮-筋上皮癌(Pulmonary epithelial-myoepithelial carcinoma)の一例

患者は65歳, 男性.発熱, 咳を主訴に受診.気管支鏡検査では左B^<1+2>_aにpolyp状の隆起が認められた.同部位の生検では核異型が目立たないため経過観察されていたが, 肺炎症状を繰り返すようになったため入院となった.胸部CT検査では左S^<1+2>に径約1.0cm大の腫瘤を認めた.診断は確定していなかったが, 悪性の可能性も否定できず, 左肺上区切除を施行.切除標本では腫瘍は左B^<1+2>内に壁外性にポリープ状増殖しており, 径1.4×1.0×0.8cm大であった.病理組織所見は腺管と紡錘形細胞が混在し増殖する二相性の腫瘍で, 免疫染色では腺管と紡錘形細胞の一部がkeratin陽性, 紡錘形細胞の大部分がα-smooth muscle actin陽性であった.以上よりPulmonary epithelial-myoepithelial carcinomaと診断された.術後約4年1ヵ月経過した現在も再発を認めていない.

Epithelial-myoepithelial carcinoma of the lung: Immunohistochemical and ultrastructural observations and review of the literature

Epithelial-myoepithelial carcinoma is a rare low-grade malignant salivary gland neoplasm that most commonly occurs in the parotid gland but can also arise in minor salivary glands. We report a case of a primary epithelial-myoepithelial carcinoma of the lung. The patient is a 55-year-old black woman who presented with increasing shortness of breath and productive cough of at least 3 months duration. A left lower lobe endobronchial lesion was identified radiographically. Surgical resection of the lesion was performed, obtaining a circumscribed, nonencapsulated 3.9 cm tan mass which was attached to the inner wall of the lateral basal segment bronchus. A biphasic proliferation of epithelial (cytokeratin positive; S-100 protein and muscle-specific actin negative) and myoepithelial (S-100 protein and muscle-specific actin positive with focal weak cytokeratin positive) cells was identified by immunohistochemical and ultrastructural analysis of formalin-fixed tissue. The patient is disease free 7 months after resection. Pulmonary epithelial-myoepithelial carcinoma likely derives from the submucosal bronchial glands and should be added to the growing list of salivary gland-type neoplasms that may occur as primary pulmonary neoplasms. Because its histology is identical to salivary epithelial-myoepithelial carcinoma, pulmonary epithelialmyoepithelial carcinoma should be considered a low-grade malignant neoplasm and should be designated as epithelial-myoepithelial carcinoma in preference to other terms that may not convey its malignant potential. Although follow-up on reported cases is limited, lobectomy with negative bronchial margin should be curative.