doi:10.1510/icvts.2011.270934
Interactive CardioVascular and Thoracic Surgery 13 (2011) 226-228
www.icvts.org
Case report - Thoracic oncologic
Primary pulmonary myoepithelial carcinoma Ilir Hysi*, Hélène Wattez, Lotfi Benhamed, Henri Porte Pôle de Chirurgie Thoracique, Hôpital Albert Calmette, CHRU Lille, 59037 Lille Cedex, France Received 7 March 2011; received in revised form 26 April 2011; accepted 8 May 2011
Abstract Primary salivary gland-type tumors of the lung are rare neoplasms. The pulmonary myoepithelial carcinoma belongs to this group. Since it was first described in 1998, we have identified only seven actual cases reported in the literature so far. We describe the case of a nonsmoker 60-year-old Caucasian female, who was referred to our institution for the treatment of three peripheral nodules. Her medical history revealed that a wedge resection, for pulmonary myoepithelial carcinoma, was performed in another center 15 months previously. After resection of the current nodules, the histological findings showed three myoepithelial carcinomas of the lung. There was no vascular or lymphatic invasion. The hilar and mediastinal lymph nodes were negatives. The patient is doing well without any sign of recurrence. Herein we shall discuss the case of a primary pulmonary myoepithelial carcinoma in a female and propose a brief review of the literature. 2011 Published by European Association for Cardio-Thoracic Surgery. All rights reserved. Keywords: Lung cancer; Myoepithelial carcinoma; Salivary gland-type tumor
1. Introduction Myoepithelial tumors are mainly encountered in the salivary glands and, at a lower incidence, in the sweat glands or in the breast. They are extremely rare in the lung. Many of these primary lung carcinomas showing features of salivary gland-type neoplasms are mucoepidermoid carcinomas and adenoid cystic carcinomas. The primary pulmonary myoepithelial carcinoma is a rare neoplasm that is thought to arise from the submucosal bronchial glands of the lower respiratory tract, which are considered as a form of minor salivary glands. Various benign and malignant tumors of these structures have occasionally been reported in the lung. Since it was first described by Higashiyama et al. [1] in 1998, we have identified only seven actual cases reported in the literature so far, all but one of them Japanese male patients. This report describes the case of a Caucasian female, presenting a primary myoepithelial carcinoma of the lung, and reviews its limited literature. 2. Case report A non-smoker 60-year-old female was referred to our institution for the treatment of three peripheral nodules. The patient was asymptomatic. Chest roentgenogram revealed a right basal shadow (Fig. 1a). Computed
*Corresponding author. Tel.: +33-3-20444559; fax: +33-3-20444890. E-mail address:
[email protected] (I. Hysi). 2011 Published by European Association for Cardio-Thoracic Surgery
tomography (CT)-scan detected a total of three nodules. Two of the nodules were in the left lower lobe and the other nodule was in the right lower lobe (Fig. 1b). Her medical history revealed that a wedge resection, for pulmonary myoepithelial carcinoma, located in the left lower lobe, was performed in another center 15 months previously. The initial tumor measured 25 mm and was isolated. There was no lymphatic or vascular invasion. We performed a new staging workup including an abdominal and a brain CT-scan, both of which were normal, a bronchoscopy, showing no endo-bronchial tumor and a PET-scan revealing only one hyper metabolic nodule in the right lower lobe. The surgery was carried out with two sequential thoracotomies, right and later left. The macroscopic aspect of the tumors was nodular and well circumscribed (Fig. 1c). After resection of the current nodules, the histological findings showed a biphasic tumor composed both of spindle cells and round cells with clear cytoplasm. These cells mainly have oval nuclei without significant atypia (Fig. 1d). Nine mitoses were present per 10 High Power Fields (HPFs). Immunohistochemical staining showed positivity of the tumoral cells for smooth muscle actin (Fig. 1e) and desmin markers but was negative for caldesmon and AE1/AE3 markers. There was no vascular or lymphatic invasion and no necrosis. The transcripts specific of synovial sarcoma were not detected. The diagnosis retained was myoepithelial carcinoma and was made after excluding solitary fibrous tumor, sarcomatoid carcinoma, leiomyosarcoma, sclerosing hemangioma and synovial sarcoma. The hilar and mediastinal lymph nodes were negatives. The patient is doing well without any sign of recurrence at 10 months follow-up.
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Fig. 1. a) Chest roentgenogram showing a right basal shadow (arrow). b) CT-scan showing three peripheral nodules (arrows). c) Per-operative view of the right nodule (arrow). d) Tumor composed of round cells with clear cytoplasm and no nuclear atypia. HES X200. e) Anti-smooth muscle actin: intense and diffuse immunostaining in tumoral cells. X200. CT, computed tomography.
3. Discussion Myoepithelial carcinoma of the lung is a very rare tumor showing only myoepithelial differentiation without any ductal formation. We were only able to find seven cases described in the English literature (Table 1) [2–6]. The benign counterpart of this tumor was documented in 1987 by Strickler et al. [7]. Frequently there is a confusion between ‘myoepithelioma’, ‘myoepithelial carcinoma’ and ‘epithelial-myoepithelial carcinoma’ of the lung. As myoepithelial carcinoma and epithelial-myoepithelial carcinoma of the salivary glands are distinguished by the presence or absence of ductal cells, their pulmonary counterparts should be differentiated also. In fact in all the cases reporting a
myoepithelioma or a myoepithelial carcinoma of the lung there was no epithelial evidence, such as ductal or tubular structures. This first histological separation is of outmost importance for the patient’s prognosis. As pointed out by Nguyen et al. [8] in a recent review of 23 cases of pulmonary epithelial-myoepithelial tumors, these neoplasms are low-grade lesions without recurrences or metastasis described after resection. Separation of myoepithelial carcinoma from myoepithelioma of the lung is also important, and this is primarily based on cellular abnormalities and infiltrative growth. Both of these tumors consist exclusively of myoepithelial cells with or without malignant histological features, respectively. Tanahashi et al. [5] reviewed only four cases of myoepithelioma of the lung in the literature. All these
Table 1. Previously reported cases of myoepithelial carcinomas Case author
Age
Sex
Smoking
Location
Tumor size
Mitotic rate (HPFs)
Metastasis
Higashiyama et al. [1] Higashiyama et al. [1] Sekine et al. [2] Miura et al. [3] Masuya et al. [4] Tanahashi et al. [5] Sarkaria et al. [6] Present case
58 58 NA 46 48 76 63 60
M M NA M M M F F
+ + NA NA + + − −
Endo-bronchial Endo-bronchial NA Endo-bronchial Peripheral Peripheral Peripheral Peripheral
38 mm 60 mm NA 65 mm 15 mm 22 mm 130 mm 25 mm
Sporadic Numerous NA 13/10 5/10 32/10 NA 9/10
Yes, Yes, Yes Yes, No Yes, Yes, Yes,
lung brain liver lung
Case Report
F, female; HPFs, high power fields; M, male; NA, not available.
soft tissue liver
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tumors have a low mitotic rate (
