Epithelial-myoepithelial carcinoma of the lung: a case report

Abstract

BackgroundPulmonary 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 presentationA 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.ConclusionsAlthough 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.

Pulmonary epithelial–myoepithelial carcinoma without AKT1, HRAS or PIK3CA mutations: a case report

“…EMC of the salivary gland was first described by Donath et al in 1972 [9]. EMC is characterized by a biphasic morphology, with an inner layer of duct-like structures composed of epithelial cells and a surrounding layer of myoepithelial cells immunoreactive for S-100 and smooth muscle actin [1,2,6]. The tracheobronchial glands are considered counterparts of the minor salivary glands in the respiratory tract and can develop similar tumors.…”

“…Salivary gland-type tumors of the lung account for 0.1-1% of all primary lung carcinomas, among which mucoepidermoid carcinoma is the most frequently observed histological subtype, followed by adenoid cystic carcinoma and then EMC [4,5]. Recently, Nakashima et al conducted a literature review of 56 patients (32 females and 24 males; average age [range], 56 years) with pulmonary EMC [6]. Of these, 45 patients had tumors localized in the central airway within segmental bronchi appearing to be endobronchial masses.…”

“…The size of the tumors varied from 0.7 to 16 cm in diameter (average 2.5 cm). According to the histopathological characteristics, three distinct histological subtypes of pulmonary EMC were reported: (1) EMC with two ductal components, defined as a characteristic feature of this tumor, (2) EMC with a solid component consisting mainly of spindle-and polygonal-shaped myoepithelial cells, and (3) EMC consisting mainly of myoepithelial cells with increased nuclear atypia, referred to as myoepithelial anaplasia [6,[12][13][14]. Seethala et al reported that patients with myoepithelial anaplasia had a poorer survival compared with others [15].…”

“…Primary salivary gland-type tumors of the lung account for 0.1-1% of all primary lung carcinomas, and the majority are mucoepidermoid or adenoid cystic carcinomas [4,5]. EMC is a rare subset of salivary glandtype tumor of the lung, with only 56 cases previously reported in the English literature [6]. Because of its rarity, molecular information on this tumor type is not sufficient.…”

Pulmonary Epithelial–Myoepithelial Carcinoma Without AKT1, HRAS or PIK3CA Mutations: A case report

“…Primary salivary gland-type tumors of the lung account for 0.1-1% of all primary lung carcinomas, and the majority are mucoepidermoid or adenoid cystic carcinomas [4][5]. EMC is a rare subset of salivary gland-type tumor of the lung, with only 56 cases previously reported in the English literature [6]. Because of its rarity, molecular information on this tumor type is not su cient.…”