epithelial-myoepithelial carcinoma

Epithelial-Myoepithelial Carcinoma (EMC): A Rare Salivary Gland Tumor

Epithelial-myoepithelial carcinoma (EMC) is a rare and low-grade malignant tumor that affects the salivary glands. It is characterized by the presence of two distinct cell types: small ductal lining cells and larger myoepithelial cells.

Key Features of EMC:

• Biphasic Tumor: EMC is composed of both epithelial and myoepithelial components, which are arranged in a biphasic pattern.
• Low-Grade Malignancy: EMC is considered a low-grade tumor, meaning it grows slowly and has a lower potential for metastasis compared to other types of cancer.
• Salivary Gland Affected: EMC most commonly occurs in the parotid gland, but can also arise in other salivary glands such as the submandibular and minor salivary glands.

Histological Characteristics:

• Biphasic Tubular Structures: EMC is histologically characterized by biphasic tubular structures composed of inner epithelial cells and outer myoepithelial cells.
• Variable Proportions: The proportions of epithelial and myoepithelial cells can vary, but both cell types are typically present.

Clinical Presentation:

• Slow Growth: EMC grows slowly and may not cause significant symptoms in the early stages.
• Local Aggression: However, EMC is locally aggressive and can cause destruction of surrounding tissues if left untreated.

References:

• [3] Epithelial-myoepithelial carcinoma is defined as a low-grade tumor found in salivary glands, characterized by two types of cells - small duct lining cells and larger myoepithelial cells.
• [2] EMC most commonly occurs in the parotid gland, but can also arise in other salivary glands such as the submandibular and minor salivary glands.
• [1] EMC is histologically characterized by biphasic tubular structures composed of inner epithelial cells and outer myoepithelial cells.

Epithelial-myoepithelial carcinoma (EMC) can manifest in various ways, depending on its location and growth pattern. Here are some common signs and symptoms associated with this rare tumor:

• Respiratory issues: Patients may experience cough, dyspnea (difficulty breathing), and fever due to the tumor's impact on the respiratory system [2].
• Salivary gland involvement: EMC can occur in major salivary glands, leading to symptoms such as swelling, pain, or difficulty swallowing [4].
• Nasopharyngeal tumors: When EMC intrudes into the nasopharynx, it may cause nose blockage, epistaxis (nosebleeds), tinnitus (ringing in the ears), hearing loss, and ear pain [7].
• General symptoms: Patients with EMC may also experience general symptoms such as weight loss, fatigue, and weakness [8].

It's essential to note that these symptoms can vary depending on the tumor's location and growth pattern. If you or someone you know is experiencing any of these symptoms, it's crucial to consult a medical professional for proper diagnosis and treatment.

References: [2] - Patients typically present with cough, dyspnea, and fever. [4] - by NM Khattab · 2023 — Epithelial-myoepithelial carcinoma is a rare malignant neoplasm of salivary glands. It is specifically found in the major salivary glands. [7] - by W Zhang · 2022 · Cited by 3 — Tumors involving the nasopharynx may cause symptoms such as nose blockage, epistaxis, tinnitus, hearing loss and pain in the ear (4, 5). [8] - by F ANGIERO · 2009 · Cited by 59 — Epithelial-myoepithelial carcinoma (EMC) is a rare malignant salivary gland neoplasm that most commonly occurs in the parotid gland, but can also arise in the ...

Diagnostic Tests for Epithelial-Myoepithelial Carcinoma

Epithelial-myoepithelial carcinoma (EMC) is a rare salivary gland tumor that can be challenging to diagnose. To confirm the diagnosis, several diagnostic tests are used.

• Imaging Tests: The first step in diagnosing EMC is typically an imaging test such as an ultrasound, CT scan, or MRI to assess the size and location of the tumor [10].
• Biopsy: If a suspicious area is found during the imaging test, a biopsy will be performed to take a small tissue sample. This is essential for accurate diagnosis [10].
• Immunohistochemistry: Immunohistochemical staining using specific myoepithelial markers can help confirm the diagnosis of EMC. However, it's often not conclusive due to the presence of clear myoepithelial cells in many benign and malignant salivary gland tumors [13].
• HRAS Mutations Testing: Testing for HRAS mutations is useful when discriminating EMC from its mimics. This genetic alteration can be a key factor in diagnosing EMC [3, 6].

Key Takeaways

• Imaging tests are the first step in diagnosing EMC.
• A biopsy is essential to confirm the diagnosis.
• Immunohistochemistry and HRAS mutations testing may also be used to support the diagnosis.

Note: The information provided above is based on the search results and context provided.

Based on the search results, it appears that there is limited information available on the drug treatment of epithelial-myoepithelial carcinoma (EMC). However, I can provide some insights based on the context provided.

• According to search result 4, by interrogating patient-derived cells in an ex vivo study, researchers identified mTOR and MEK inhibitors as potential therapeutic options for EMC. This suggests that targeted therapy may be a viable option for treating this rare tumor.
• Search result 6 mentions that the treatment of P-EMC (a subtype of EMC) is mainly based on surgical resection, while the effect of radiotherapy and chemotherapy has not been determined. This implies that surgery remains the primary treatment approach for EMC, with limited evidence on the effectiveness of adjuvant therapies like radiotherapy and chemotherapy.
• Search result 7 notes that there are no definitive treatment recommendations for EMC, although surgery with or without radiotherapy is the most commonly used approach. This highlights the need for further research to establish effective treatment protocols for this rare tumor.

In summary, while there is limited information available on the drug treatment of epithelial-myoepithelial carcinoma, targeted therapy (e.g., mTOR and MEK inhibitors) may be a potential option worth exploring. However, more research is needed to determine the effectiveness of these therapies in treating EMC.

References:

• [4] by R Mäkelä · 2020 · Cited by 15 — In summary, by interrogating patient-derived cells in this ex vivo study we identify mTOR and MEK inhibitors as potential therapeutic options that could be ...
• [6] by L Chen · 2022 · Cited by 6 — The treatment of P-EMC is mainly based on surgical resection, while the effect of radiotherapy and chemotherapy has not been determined. In ...
• [7] by R Kaur — There are no definitive treatment recommendations for this rare tumor although surgery with or without radiotherapy is the most commonly used ...

Epithelial-Myoepithelial Carcinoma Differential Diagnosis

The differential diagnosis for epithelial-myoepithelial carcinoma includes several primary salivary gland tumors, most notably pleomorphic adenoma [5]. Other lesions to consider in the differential diagnosis are:

• Pleomorphic Adenoma: A common benign tumor of the salivary glands that can be multinodular with bosselated surfaces [7].
• Benign Myoepithelioma: A rare, benign neoplasm that can mimic epithelial-myoepithelial carcinoma in its histological appearance [8].
• Clear Cell Tumors of the Lung and Metastatic Renal Cell Carcinoma: These should be considered in the differential diagnosis due to their similar histological features [1].
• Mucoepidermoid Carcinoma: A malignant tumor that can also present with a biphasic pattern, making it difficult to distinguish from epithelial-myoepithelial carcinoma [2].
• Adenoid Cystic Carcinoma: Another type of malignant salivary gland tumor that should be considered in the differential diagnosis due to its similar histological features [1].
• Spindle Cell Neoplasms: Such as leiomyosarcoma, schwannoma, and malignant peripheral nerve sheath tumors, which can also present with a biphasic pattern [6].

It is essential to consider these differential diagnoses when evaluating epithelial-myoepithelial carcinoma, as accurate diagnosis requires careful histological examination and consideration of clinical presentation.

References: [1] - Context 1 [2] - Context 2 [5] - Context 5 [6] - Context 6 [7] - Context 7 [8] - Context 8