Epithelial-Myoepithelial Carcinoma of the Minor Salivary Glands: Case Series with Comprehensive Review

Epithelial-myoepithelial carcinoma with multiple recurrences: An unusual presentation

Epithelial-myoepithelial carcinoma (EMC) is a type of malignant salivary gland tumors that is extremely rare. EMC primarily affects major salivary glands, particularly the parotid gland, but minorsalivary glands are also affected. It contributes less than 0.5-1% of all salivary gland neoplasms. Multiple recurrences are relatively rare with EMC. There have been very few reports of multiplerecurrences in the literature. Biphasic tubular structures composed of externalclear cells and inner ductal cells are the distinguishing histopathological feature. However, histological variation is prevalent, making a precise diagnosis challenging. We present a case of EMC that had multiple recurrences during a six-year period.

Epithelial-Myoepithelial Carcinoma of the Maxilla Arising From Minor Salivary Glands of Hard Palate: A Rare Case Report

Epithelial-myoepithelial carcinoma is a rare malignant neoplasm of salivary glands. It is specifically found in the major salivary glands. The cases that emerge from minor salivary glands are rarely described. Histologically, it commonly exhibits a characteristic biphasic pattern consisting of epithelial and myoepithelial components. The histopathological resemblance to other benign and malignant neoplasms that also display myoepithelial characteristics makes the differential diagnosis challenging. Each differential diagnosis requires a very different management approach. Considering the difficulties of anatomopathological diagnosis and the rarity of epithelial-myoepithelial carcinomas emerging from minor salivary glands, we report a rare epithelial-myoepithelial carcinoma case of minor salivary glands in a 58-year-old woman. She was referred for a palatal swelling, evolving for more than 35 years, and reported recent pain and nasal obstruction. The mucosal swelling was located in the left maxilla within the hard palate, of a 45-mm-long axis crossing the medial line and extending to the premaxilla, without cervical lymph node involvement. A computed tomography scan revealed a palatal lesion involving the left and the right maxilla. Furthermore, the superior alveolar process, both left and right maxillary sinuses, the nasal cavities, and the nasal septum were included in the lesion. The final diagnosis was difficult to confirm despite multiple biopsies and was determined only from the excised specimen. The diagnosis of this tumor was challenging due to the clinical and histological similarities with other salivary tumors. The aim of this case report is to shed light on the distinctive features of these tumors and explore optimal screening and related management strategies.

Epithelial Myoepithelial Carcinoma Masquerading as Simple Parotid Cyst in a Middle Aged Male

Epithelial-Myoepithelial Carcinoma (EMC) is a very rarely seen biphasic tumour typically seen in older females and constitutes 0.5-1% of all salivary gland neoplasms. The parotid gland is most often involved and occasionally there may be involvement of submandibular and minor salivary glands. Clinical picture often reveals benign nature of the disease. Computed tomography (CT) and magnetic resonance appearances are non-specific and the cytological diagnosis may be challenging, thus more accurate diagnosis can only be made by histological and immunohistochemical study. There is no consensus regarding the optimal treatment of this neoplasm, largely due to its rarity. Wide surgical excision with a clear margin is the treatment of choice because of the tumour's tendency to infiltrate locally. Adjuvant radiotherapy is often required in cases of large primary tumours and positive surgical margins. The tumour may commonly recur locally after resection in 30-50% of cases. We herein present an unusual case of a 46-year-old male who presented with cystic swelling of left parotid gland and diagnosed as EMC on histopathology and immunohistochemical examination. The patient was treated with surgical resection followed by post-operative radiotherapy.

Epithelial-myoepithelial carcinoma of retro-molar trigone: Unveiling the mystery of rare diagnosis

Epithelial-myoepithelial carcinoma (EMC), a low-grade malignant neoplasm of glandular origin, most commonly involves major and occasionally minor salivary glands. It is rare in minor salivary glands such as hard and soft palate, buccal mucosa, tongue, and so on, frequently affecting geriatric females. EMC comprises diverse histo-pathologic features of an epithelial, myoepithelial de-lineating biphasic pattern along with clear cells, sometimes oncocytic differentiation. Aberrant histo-pathologic features in EMC need judicious discrimination from alike entities, which facilitates appropriate surgical management. Here, we present an unusual case report of EMC in the left retro-molar trigone region in a 60-year-old male patient, the complete diagnosis of which was based on clinical, radiological, histo-pathological, and immuno-histo-chemical features.

Epithelial–myoepithelial carcinoma of the nasopharynx: A case report and review of the literature

Background

Epithelial–myoepithelial carcinoma (EMCa) is a rare low-grade malignant tumor that most commonly occurs in the salivary glands, with approximately 320 cases having been reported worldwide. Here, we report the third case of EMCa occurring in the nasopharynx. Rare cases in the breast, pituitary gland, lacrimal gland, nose, paranasal sinus, nasal cavity, trachea and bronchus, lung, and even the pleura mediastinalis have also been reported. Histopathology and immunohistochemistry are useful for confirming the diagnosis of EMCa, which is characterized by biphasic tubular structures composed of inner ductal and outer clear myoepithelial cells and stains for different markers in each layer. However, because of the rarity of EMCa, the clinicopathological characteristics and treatment of these patients remain unclear.

Case presentation

We report a rare case of EMCa of the nasopharynx. A 51-year-old man presented with a 5-month history of pain while swallowing and aggravation accompanied by right ear tinnitus lasting for 1 month. Nasopharyngoscopy and magnetic resonance imaging (MRI) of the nasopharynx and neck revealed a 5.6 cm × 3.4 cm × 3.1 cm mass in the nasopharyngeal space, invasion of the right cavernous sinus, and lymph node enlargement in the right retropharyngeal space. On 17 April 2019, based on the histopathological and immunohistochemical features, a final diagnosis of EMCa of the right nasopharynx was made. The patient underwent concurrent chemoradiotherapy (CCRT), and his symptoms were relieved after treatment. On 10 January 2022, nasopharynx MRI and biopsy revealed local recurrence, but chest and abdominal computed tomography (CT) showed no obvious signs of metastasis. The local recurrence-free survival (LRFS) period was 33 months.

Conclusion

To the best of our knowledge, this is the third reported case of EMCa in the nasopharynx and the only case of EMCa in the nasopharynx treated with CCRT, and a partial response was achieved. Therefore, to improve the quality of life and prognosis of patients with unresectable tumors, we believe that CCRT is a suitable option. Further clinical observations are required to elucidate the pathophysiology and prognosis of EMCa.

Targeted Therapy, Chemotherapy, Immunotherapy and Novel Treatment Options for Different Subtypes of Salivary Gland Cancer

Surgical resection remains the first line treatment for salivary gland cancer (SGC). In the case of locally advanced disease, surgery is followed by adjuvant radiotherapy. Surgical resection should be favored in resectable locoregional recurrent disease as well, and even the complete resection of all distant oligometastases has clinical benefit for the patients. For inoperable and disseminated metastatic disease, a multitude of systemic therapies including chemotherapy, targeted therapy, and immunotherapy are available. In this review, the current therapeutic options for inoperable recurrent or metastatic SGCs are summarized. Systemic treatment can achieve prolonged progression-free and overall survival, while the overall prognosis remains poor. Current clinical trials include only a limited number of patients and mostly combine different histologic subtypes. Additionally, no randomized controlled trial comparing different therapeutic options has been performed. In the future, further studies with a larger patient cohort and ideally only one histologic subtype are needed in order to improve the outcome for SGC patients. However, this may be difficult to accomplish due to the rarity and diversity of the disease. Additionally, molecular analyses need to be performed routinely in order to individualize treatment and to go one step further towards precision medicine.