Myoepithelioma of parotid gland presenting as infra-auricular subcutaneous mass

Myoepithelial Carcinoma of the Floor of the Mouth: A Rare Salivary Gland Tumor in an Unusual Location

Myoepithelial carcinomas are rare malignant salivary gland tumours encountered most commonly in the parotid gland and are amenable to surgical resection. However, when they occur at complex anatomical locations, complete resection becomes difficult due to their locally aggressive nature. Here we describe a case of a large myoepithelial carcinoma arising in the floor of the mouth and involving major structures at the skull base.

A 30-year-old female presented with a slow-growing mass in the oral cavity. Computed tomography (CT) scan showed a heterogeneous appearing lesion in the mouth floor measuring 6.7 x 5.8 x 7.3 cm. Superiorly, the lesion was extending up to the skull base, laterally extending up to the parotid gland and inferiorly up to the submandibular gland. This lesion was also encasing the internal carotid artery. Incisional biopsy under local anaesthesia was performed, and the specimen was sent for histopathological analysis. Microscopic examination showed a neoplastic lesion composed of sheets of cells with oval nuclei and clear cytoplasm with a myxoid background. Immunohistochemical expression of pan-cytokeratin (CKAE1/AE3), p63, anti-smooth muscle actin (ASMA) and glial fibrillary acidic protein (GFAP) supported the diagnosis of myoepithelial neoplasm. The patient then underwent excision of the mass followed by histological analysis, which further showed microscopic evidence of infiltration into the surrounding tissue along with areas of atypia and significant mitoses. These morphological findings supported the diagnosis of myoepithelial carcinoma. The excised tumour was reaching up to the excision margin.

Myoepithelial carcinomas are rare malignant tumours with diverse histomorphological patterns frequently present as a diagnostic challenge. The mainstay of treatment is complete surgical excision with disease-free margins, which can be challenging due to local aggressiveness and large size of these tumours. When these tumours occur in complex anatomical locations, complete excision becomes difficult, resulting in a dismal prognosis.

Voluminous Myoepithelioma of the Minor Salivary Glands Involving the Base of the Tongue

Myoepithelioma is an extremely rare tumour subtype and diagnosis is based on a wide variation of cellular morphology. FNAC specimens do not always suffice for a definitive differential diagnosis which depends on histology and immunohistochemistry of the lesion. Case Presentation. A 54-year-old female came to our attention with dysphagia and dyslalia of 6-month standing. Ear, Nose, and Throat (ENT) examination revealed a voluminous mass on the right portion of the base of her tongue, where postcontrast T2-weighted Magnetic Resonance Imaging (MRI) evidenced a hyperintense lesion. The fine-needle aspiration specimen taken for cytology was not diagnostic, as a differential diagnosis between myoepithelioma and a malignant neoplasm of the salivary glands necessitates parameters that cytology alone cannot provide. Therefore, the whole lesion was excised by diode laser through a transoral approach. Histology and immunohistochemistry of the completely excised lesion confirmed a myoepithelioma.

Myoepithelioma of the soft palate: a case report

Myoepitheliomas are rare benign tumors of myoepithelial cell origin, most commonly seen in parotid gland. These tumors are also reported in oral cavity, soft palate being the most common site of involvement. Imaging findings are nonspecific, and histopathology is necessary to differentiate from other tumors. Our case showed mildly enhancing well-circumscribed mass in soft palate with histological findings consistent with myoepithelioma. The aim of this case report is to increase the awareness about this rare benign tumor regarding its morphological, histopathological, and radiological features along with its possible differential diagnosis.

Myoepithelioma of the Parotid Gland Presenting as a Retroauricular Cutaneous nodule: A Case Report

We are reporting a case of recurrent myoepithelioma of the parotid gland, that emerged as a cutaneous mass. She had a retroauricular subcutaneous mass with an underlying diagnosis of a cutaneous myoepithelioma, which was excised at a hospital's Dermatology Department 2 years earlier. The tumour was observed above the platysma and it was considered as a cutaneous myoepithelioma without the parotid gland structures. She had undergone a partial parotidectomy approximately 20 years earlier. At her first visit to our department, there was no evidence of facial nerve palsy or cervical lymphadenopathy. The radiological findings showed a multinodular growing mass of the parotid gland, just beneath the retroauricular skin and a total parotidectomy was performed. It was considered that even if the cutaneous mass emerged, the relationship between the cutaneous mass and the parotid gland should be pre-surgically examined by computed tomography (CT) or Magnetic resonance image (MRI). A long-term continuous follow-up was also needed.

Myoepithelioma of the soft palate: a case report giving special attention to the differential diagnosis

BACKGROUND

Myoepitheliomas are rare tumours that may generally arise from the minor or major salivary glands. The differential diagnosis of this tumour should be performed along with several benign and malignant soft tissue neoplasms. The present case report describes an asymptomatic mass that arose in the soft palate of 42 year old black woman with duration of the six months.

METHODS

An incisional biopsy of soft palate lesion was carried out and submitted for histological evaluation under the clinical hypothesis of salivary gland tumour. To confirm the myoepithelial nature of neoplastic cells the immunohistochemical reactions for smooth-muscle actin, cytokeratins and S100 were performed.

RESULTS

The histological examination revealed the presence of tumour originating from a minor salivary gland and covered by a stratified squamous oral epithelium. The tumour cells were arranged in order to form a myxoid pattern and, individually, small and/or medium spindle-shaped cells with predominantly round or ovoid nuclei, as well as epithelioid and plasmocytoid cells were noted. The stroma was myxomatous and no ductal or syringomatous epithelial structures were observed. Following the histological and immunohistochemical diagnosis of myoepithelioma, the lesion was surgically removed. After the surgery, a follow-up of one year showed no signs and symptoms of reccurrence.

CONCLUSIONS

The myoepithelioma should be carefully distinguished from the other soft tissue tumours, especially those arising from salivary glands, such as pleomorphic adenoma and adenoid-cystic carcinoma.

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.

Imaging of salivary gland tumours

Imaging of salivary gland tumours is a major challenge for radiologists due to the great variety of differential diagnoses. This article gives a short overview on the anatomy of the salivary glands, the epidemiology of salivary gland tumours as well as the clinical presentation and the different imaging modalities including new magnetic resonance techniques such as diffusion-weighted magnetic resonance imaging, dynamic contrast-enhanced magnetic resonance imaging and magnetic resonance spectroscopy applied in the work-up of salivary gland masses. The imaging features of different tumour types and their differential diagnoses are also discussed. Finally, staging classification and treatment options are presented.

Mioepitelioma de glândula salivar menor: uma análise imunohistoquímica de quatro casos

INTRODUÇÃO E METODOLOGIA: Realizou-se um estudo imunohistoquímico em 4 casos de mioepiteliomas, visando traçar seu perfil quanto ao grau de diferenciação das células através dos anticorpos alfa-SMA, CK 14 e vimentina, bem como investigar o índice de proliferação celular pelo anti-PCNA, além de comparamos a imunorreatividade com o tecido glandular normal adjacente ao tumor. RESULTADOS: No tecido glandular normal as células mioepiteliais exibiram marcação para alfa-SMA e CK 14, enquanto que nas células ductais somente a presença da CK 14 foi verificada. Em todos os casos foi verificada positividade para CK 14 e vimentina, porém a CK 14 esteve presente somente em células epitelióides e fusiformes, enquanto que a vimentina mostrou-se positiva também nas células plasmocitóides. A alfa-SMA não foi detectada nas células neoplásicas. Imunopositividade para o PCNA foi observada em mais de 75% do componente celular dos tumores analisados, independente do tipo. CONCLUSÕES: Concluiu-se que não houve diferença na atividade proliferativa entre os tipos celulares presentes nos mioepiteliomas e, ainda, que os resultados deste estudo sugerem que as células constituintes desta neoplasia realmente representam células da linhagem mioepitelial, mas em diferentes estágios de diferenciação.

Myoepithelioma of minor salivary gland - An immunohistochemical analysis of four cases

Introduction and Methods

We performed an immunohistochemical study in four cases of myopitheliomas with objective to realize a profile in respect of differentiation grade by the monoclonal antibodies CK14, vimentin and alph-SMA, besides to investigate the cell proliferation by anti-PCNA, besides, we compare the immunoreactive with glandular normal tissue.

Results

In the glandular normal tissue the myoepithelials cells had shown expression for alpha-SMA and CK 14, while that in the ductals cells, only the presence of CK 14 was verified. All the cases was verified positivy for CK 14 and vimentin, however, CK 14 had been present only in epithelioid and fusiform cells, while that the vimentin revealed positive also in the cytoplasm of the plasmocytoid cells. alpha-SMA was not detected in the neoplasic cells. Immunopositivity for the PCNA was observed in more than 75% of the cellular component of the analyzed tumors, independent of the cellular type.

Conclusions

We concluded that it did not have difference in the proliferative activity among the cellular types presents in the myoepitheliomas and, still, the results of this study suggest that the constituent cells of this neoplasia one really represent cells of the mioepitelial ancestry, but in different stages of differentiation.