Introduction:
Maxillary antral carcinoma is a rare head and neck malignant tumor. They are usually diagnosed late, despite an increase in size within the confinements of the maxillary sinus and the symptoms are manifested late. Maxillary antral cancer is commonly reported in Asian countries. Despite being an uncommon tumor, it becomes important to raise awareness among the general population and medical oncologists. The major predisposing factors of the tumor include harmful chemicals and oncogenic viruses. It has a very poor prognosis.
What Is the Epidemiology of Maxillary Antral Carcinoma?
Approximately three to four percent of all oral tumors originate from the maxillary sinuses. Almost 85 percent of tumors arise from the maxillary antrum. Microscopically, these tumors are squamous cell carcinomas in most instances. The tumor is most commonly present in Asian and African people. The tumor is rarely present in European and North American populations. Middle-aged people are more likely to be affected with the tumor occurring more commonly in males than females. People that fall in the age group of 45 to 65 years are more likely to be affected by the tumor.
What Is the Etiology of Maxillary Antral Carcinoma?
The etiology of maxillary antral carcinoma is not completely known, but it is believed that chronic maxillary sinusitis is the most common etiologic factor for carcinoma. Chronic (long-term) maxillary sinusitis causes squamous metaplasia of the respiratory epithelial cells. This is probably the most known origin of most of the maxillary antral cancers. Some patients report a long-standing history of the signs and symptoms of chronic sinusitis. These signs and symptoms are reported prior to the manifestation of the signs and symptoms of the progressive maxillary antral tumor. Some of the most common risk factors include harmful chemical exposure, smoking, alcohol consumption, wood dust exposure, Epstein-Barr virus (EBV), and human papillomavirus (HPV) viral infections.
What Are the Clinical Features of Maxillary Antral Carcinoma?
The clinical symptoms of the tumor include:
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There is stiffness present unilaterally on the side of the tumor.
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The tumor can restrict mouth opening and also cause obstruction.
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Abnormal bulging of the eyes (proptosis).
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The patient may see two images of a particular object (double vision or diplopia).
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Severe pain will be present similar to that occurring at the time of toothache.
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There will be palatal enlargement.
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Ulceration of the palate also occurs in advanced tumor cases.
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Middle-aged men are more commonly affected by maxillary antral carcinoma.
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The early signs and symptoms are not present in this carcinoma.
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There is a complaint of intraoral mass.
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Facial pain and a feeling of numbness are also present.
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There is swelling of the affected part and nasal obstruction present.
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Larger lesions may cause severe headaches because of the proximity of the maxillary sinus to the brain.
What Is the Histopathology of Maxillary Antral Carcinoma?
Most tumors are known to originate from the paranasal sinuses. Approximately 80 percent of the tumors are squamous cell carcinoma. 10 to 11 percent of the tumors are of adenoid cystic type. The remaining ones are adenocarcinoma (cancer of the glandular cells), verrucous (proliferative) carcinoma, malignant melanoma (most serious skin cancer), lymphomas (cancer of the lymphatic system), and sarcoma (cancer of the bone or soft tissues) histologic types that frequently exhibit metastases.
What Are the Radiographic Features of Maxillary Antral Carcinoma?
The tumor mass usually appears as an irregular radiopacity within the radiolucent maxillary sinus, thereby causing the erosion of the maxillary sinus wall.
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Imaging Techniques: This technique is usually carried out to determine the exact location of the tumor mass, the extent of the tumor erosion and invasion into the surrounding structures, and identify the possible path of metastasis.
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CT Scan: CT (computed tomography) scan of the brain is performed to highlight the boundaries of this rare tumor, define the grade of bone destruction that has occurred, and to check for any intracranial invasion. The radiographic signs visible on the CT scan of the malignant antral carcinoma include osteolysis (bony destruction) of the walls of the maxillary sinus, mixed radiopaque and radiolucent mass within the sinus, and heterogeneous mass present in the nasal cavity. CT scan is considered to be an accurate mode of imaging technique having a higher accuracy level. It helps evaluate the bone remodeling and skull base bony erosion along with sinus wall erosion more accurately. CT scan has the ability to scan the bony wall of the orbit as well as the adjacent fatty tissue.
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MRI: Magnetic resonance imaging (MRI) is pivotal in determining the various factors that will play a crucial role in planning tumor resection surgery. These factors include invasion in the orbital wall, tumor spread in small nerves, invasion of the cranial base, tumor spread in the intracranial tissues, and involvement of the masticatory and parapharyngeal spaces by the maxillary antral carcinoma. MRI has the added advantage of a multiplanar imaging technique with suitable tissue contrast.
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Other Tests: The confirmatory diagnosis of maxillary antral carcinoma is made by microscopic examination by performing an incisional biopsy of the lesion. Nasal endoscopy can also be performed to confirm nasal involvement.
What Is the Treatment and Prognosis of Maxillary Antral Carcinoma?
Management consists of tumor resection followed by postoperative radiotherapy and chemotherapy. The tumor is rare but very aggressive in nature, destroying the adjacent tissues and structures at a very rapid rate. The survival rate is poor, with a five to six-year survival rate. Surgery is usually carried out to remove the tumor mass and to help relieve the sinus blockage. The tumor usually spreads to adjacent tissues, bones, and lymph nodes. However, the surgical resection of the tumor poses a surgical challenge for the oncologists and surgeons performing the tumor resection.
What Is the Differential Diagnosis of Maxillary Antral Carcinoma?
The differential diagnosis of carcinoma includes
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Long-standing maxillary sinus infection like invasive fungal (mycotic) sinusitis.
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Wegener granulomatosis (an autoimmune disorder).
Conclusion
To conclude, diagnosing maxillary antral carcinoma requires a high degree of precision, a high index of doubt. It should be regarded as an aggressive, invasive tumor with worsening of the sinonasal signs and symptoms. It is a rare but persistent cancerous mass that is detected late. Radiographic imaging and microscopic confirmation using incisional biopsy are important to confirm the diagnosis of this malignant tumor. The prognosis is very bad, and the treatment involves tumor resection with chemotherapy and radiotherapy.
