Introduction
Lung or bronchogenic carcinoma is a tumor originating from lung parenchyma or lung bronchi. It is one of the highest contributing causes of death in women than breast cancers.
Mucoepidermoid carcinomas are uncommon salivary gland-type tumors that consist of cellular components such as mucin-secreting cells, squamous cells, and intermediate types of cells. These are discrete groups of lung cancers that account for less than one percent of lung cancers. They affect all ages, though 50 percent of cases are seen in individuals before the age of 30 years. It has no gender preference. Because of the rarity of this cancer, the cause of the disease is not exactly known.
What Are the Symptoms of This Disease?
The signs and symptoms of the disease are often delayed for a year or more due to its slow nature, The most common presenting symptoms of mucoepidermoid carcinoma are the symptoms that appear due to large airway obstruction or irritation. They appear as
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Hemoptysis (blood in saliva).
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Cough.
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Wheezing.
How Is Mucoepidermoid Lung Carcinoma Classified?
This carcinoma can be categorized based on macroscopic and histological examination. The macroscopic features are the features that can be visible by the naked eye and measured without dealing with the chemical components. Mucoepidermoid carcinomas are well-divided oval or round tumors, usually soft in consistency, and are sometimes hard or elastic, measuring 1.18 inches on average. They can be gray-white to pink-tan.
The main classification of this carcinoma is based on histological features. Histological features are the microscopic features that present the microscopic outline, the cells, and the activity of cellular structures. According to the World Health Organization (WHO), this classification is based on three parameters.
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Cytological Atypia - As per the cellular study, atypia refers to the presence of cellular structures that differ from the normal cell.
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Mitotic Activity - The process of cellular divisions of cells.
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Cellular Necrosis - This is the death of the cell or the body tissue.
Based on the above features, mucoepidermoid carcinoma can be classified as
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High-Grade Subtype - High-grade mucoepidermoid carcinoma has atypical cells with more necrotizing (cheese-like) cells that undergo aggressive division at an abnormal pace. High-grade carcinomas are rare to be found and have typical features, which include growth-like projections within the bronchi, with the surface of the bronchi showing carcinogenic /cancerous changes. The cell keratinization and squamous pearl are absent, with few areas of low-grade mucoepidermoid carcinoma.
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Low-Grade Subtype - These are the tumors that consist of three types of cells -mucin-secreting squamous, intermediate cells, and cystic cells with solid patterns in between. Such carcinoma has shown solid patterns as well as cystic patterns. The cystic pattern comprises cytologically bland columnar cells with mucin and cell division. At the same time, the solid areas consist of normal squamoid or intermediate cells surrounded by cystic areas. This subtype shows less atypical activities and is less aggressive as compared to high grades.
How Is Bronchial Mucoepidermoid Carcinoma Evaluated?
The condition has more radiological or pathological changes than clinical presentation. It can be confirmed and evaluated by following investigations -
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Chest X-ray - X-ray presents the features of this carcinoma as well-demarcated, oval round, or lobulated masses. Often, the signs of lung constriction, called bronchial stenosis and lung obstruction, are seen, such as mucus impaction, post-obstructive pneumonia, air trapping, and peripheral lucency.
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Computed Tomography (CT) Scan - The findings on CT for pulmonary mucoepidermoid carcinoma are non-specific. In the case of low-grade intraluminal tumors, the same type of nodules are seen, which may have obstructive change accompanied by some large lobulars that present as different types of masses from each other, containing multiple cystic structures. In some cases, the calcifications are also present.
In the case of high-grade carcinoma, mucus secretion becomes scanty due to weak differentiation. Here, cystic lesions are less common, and cell necrosis occurs more frequently than in low-grade subtypes. It should be noted that on CT, high-grade tumors show signs of common lung cancers, including metastasis.
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PET imaging - It is the positive emission tomography scan that uses radioactive material to evaluate diseases for cancerous changes. On this scan, the dimensions of these tumors range from 0.24 to 2.36 inches.
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Bronchoscopy - This imaging presents pulmonary mucoepidermoid carcinoma as a polypoid pink area.
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Histopathology - The diagnosis of this carcinoma is made by histopathological examination. Biopsy and excision specimen is evaluated for pathological changes that are confirmatory.
How Is Brochial Mucoepidermoid Carcinoma Treated?
The best choice of treatment for this carcinoma is surgical intervention. Complete surgical resection can result in better long-term survival. In cases of high-grade mucoepidermoid carcinoma, adjuvant therapy is done where the complete excision of the tumor and carcinoma is not possible. The role of chemotherapy and radiotherapy, however, remains uncertain in many cases of this carcinoma and is subject to further studies.
What Is the Prognosis of The Disease?
Despite the occasional nodal involvement and the metastasis (spread of cancer to distant organs by the bloodstream or lymph drainage), the improvement of low-grade carcinoma is seen to be excellent with the prognosis much better in children. In the case of high-grade carcinoma, the prognosis may vary, but almost 25 percent of cases show metastasis, which includes the factors of lymph node metastasis, and the positive resection margin is low.
Conclusion
This condition is managed by a professional team, which includes pulmonologists, radiologists, oncologists, and pathologists. Early and prompt diagnosis can lead to better treatment, and the prognosis is better in such cases. The palliative care in this disease, as well as the other carcinomas, should never be undermined all should always be taken care of as it helps the patient to deal well with the disease, encourages him to seek treatment, and boosts his mental and emotional well-being, which is an important aspect while dealing with the disease.
