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

Abstract

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.

The key radiologic and cytomorphologic features of oncocytic and oncocytoid lesions of the salivary gland

“…Epithelial‐myoepithelial carcinoma (EMC) is a rare neoplasm, comprising only 1% of all salivary gland tumors . Most (60%‐80%) occur in the parotid gland, however they can occur in any major or minor salivary gland . They have a slight female predominance (F:M of 1.5:1) and a wide age distribution with a mean age at diagnosis in the early 60s …”

“…90 Most (60%-80%) occur in the parotid gland, however they can occur in any major or minor salivary gland. [91][92][93][94] They have a slight female predominance (F:M of 1.5:1) and a wide age distribution with a mean age at diagnosis in the early 60s. 91 It is currently believed that there are two pathways for the development of EMC.…”

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

“…13 In our case, the use of the expander was a better treatment from the radiotherapeutic point of view, as reported in other conditions wherein the insertion of a spacer has led to advancements in the field of radiotherapy. 14,15 Conclusion PMC-L is exceedingly rare. To our knowledge, our case represents the first pediatric case with surgical treatment of PMC-L that involved the whole lung.…”

Endobronchial laser ablation in the management of epithelial-myoepithelial carcinoma of the trachea

“…Of these cases of tracheal tumours, the majority are made up of squamous cell carcinoma and adenoid cystic carcinoma, but salivary gland tumours may also occur infrequently due to the presence of submucosal glands in the trachea and bronchi [4] .…”

“…Epithelial-myoepithelial tumours are low grade, indolent malignancies of the salivary glands, most commonly the parotids, with only approximately 120 documented cases [5] , thus representing approximately 1% of salivary gland tumours [6] . They may also seldom occur in extraglandular locations such as the respiratory tract, a location which comprises a tenth of the number of cases documented [4] .…”