Sinonasal Malignancies - An Overview

What Are Sinuses?

Paranasal sinuses are small air-filled cavities present in the facial and skull bones along with nasal cavities; they occupy small anatomical space but are the origin of many sinonasal tumors. These cancer growths develop from the mucosa, seromucous glands, soft tissues, bone, cartilage, neural tissue, hematolymphoid, and odontogenic cells. The paranasal sinuses are named according to the location of the bones they are present. Following are the paranasal sinuses.

• Ethmoidal Sinus.

• Maxillary Sinus.

• Sphenoidal Sinus.

• Frontal Sinus.

What Is the Etiology of Sinonasal Malignancies?

The etiologic factors depend on the type and location of the tumor.

• Occupational exposure to wood and leather dust.

• Exposure to formaldehyde and nickel or chromium compounds

• Adenocarcinoma risk increases with wood dust, leather dust, and formaldehyde.

• Squamous cell carcinomas occur due to arsenic and welding fumes.

• There are high risks of sinonasal cancer with chemical exposures and occupational hazards in farming, construction, miners, drillers, blasters, plumbers, machinists, bakers, pastry confectionery, and the metal industry.

What Is the Pathogenesis of Sinonasal Cancer?

Exposure to hardwood dust and leather is associated with the development of sinonasal cancer. Wood dust consists of organic and inorganic components; these components are genotoxic and carcinogenic factors. In addition, it can cause DNA damage and induces the generation of reactive oxygen species in the cells. Molecular alterations are seen in intestinal-type adenocarcinoma. Human papillomavirus (HPV) is associated with a few sinonasal carcinomas. Therefore, identifying HPV in sinonasal cancers has vital clinical significance, as the presence of HPV can act as a prognosis tool and help with good income.

How Do Sinonasal Malignancies Spread?

The pattern of spread of maxillary sinus cancers differs according to the location.

• Superstructure tumors extend into the nasal cavity, ethmoid cells, orbit, pterygopalatine fossa, infratemporal fossa, and skull base.

• Infrastructure tumors often infiltrate the palate, alveolar process, gingivobuccal sulcus, soft cheek tissue, nasal cavity, masseter muscle, pterygopalatine space, and pterygoid fossa.

Symptoms of Sinonasal Tumors:

• Nasal fullness.

• Stuffiness.

• Obstruction.

• Epistaxis or bleeding nose.

• Rhinorrhea.

• Pain.

• Paresthesia to tooth mobility.

• Tooth loss.

• Proptosis.

• Diplopia.

• Lacrimation.

What Are the Risk Factors for Sinonasal Malignancies?

Sinonasal tumors are rare, consisting of three percent of tumors. They are more commonly seen in whites and males than in females. Exposure to industrial fumes, tobacco, and radiation can increase one's risk of sinonasal cancer.

What Are the Types of Sinonasal Tumors?

• Inverted papillomas.

• Squamous cell carcinoma.

• Transitional cell carcinoma.

• Adenocarcinoma.

• Adenoid cystic carcinoma.

• Melanoma.

• Neuroblastoma.

• Sarcomas.

• Lymphoma.

• Plasmacytoma.

• Giant cell tumor.

• Metastatic carcinoma.

How to Diagnose Sinonasal Malignancies?

A complete medical and physical examination and an endoscopy help with the diagnosis. The following procedure can help detect sinonasal tumors.

• A biopsy is a procedure in which tissue from the body is removed, used as a sample, and examined under a microscope to look for abnormal cells.

• Fine needle aspiration biopsy involves the removal of tissue fluid with the help of a thin needle. Fine needle aspiration is the most common biopsy used for salivary gland cancer.

• An incisional biopsy removes part of a lump or abnormal tissue sample.

Surgery is advised if cancer cannot be diagnosed from the tissue sample removed during a biopsy.

• Computed tomography (CT-scan) is a noninvasive procedure that takes different planar images of the sinuses to detect abnormalities missed in endoscopy.

• The ultrasonography imaging technique uses high-frequency sound waves and forms an image of the internal organs. This is not commonly used for sinonasal malignancies.

• Magnetic resonance imaging (MRI) is a noninvasive use of magnetic fields and radio waves to form a two-dimensional image of the sinuses.

• PET scan (positron emission tomography) uses radioactive glucose injection in a vein to form a three-dimensional image. Malignant tumor cells glow brighter in the image as malignant cells are active and absorb more glucose than normal cells.

Treatment of Sinonasal Cancers:

Patients with sinonasal cancer need a treatment planned by a team of specialists in treating cancer, surgeons, and radiation oncologists.

Treatment may include:

• Surgery.

Surgery is one of the primary and most necessary treatment modalities for the resolution of cancerous growth. The surgeon marginally excises the tumor, which also involves the healthy edges. The healthy edges are checked for dysplasia and cancerous histomorphology. The surgical procedures are accompanied by radio or chemotherapy. The surgeon can decide the surgery's approach depending on the tumor's size and location. It might be an endoscopic approach or the more conventional external approach. The surgeon takes care of the remaining structure, but several times, it involves disfigurement of the structures.

The disfigurement can be subsequently treated with secondary surgeries or prosthetic devices. Post-surgical management of malignancy may require further rounds of chemotherapy or radiotherapy. These aggressive therapies do not discriminate between healthy or malignant tissues, and the post-radiation complication affects the QOL of the patient. Reconstructive surgeries involve grafts from other sites of the patient, which may lead to a second surgical site.

Sometimes the surgical procedure leaves patients with facial disfigurement and speech and swallowing difficulties. Tumor surgery is followed by reconstructive surgery to deal with the problems, usually using tissue from elsewhere in the body. Post-surgical rehabilitation is essential for the physical as well as psychological healing of the patient. Radiation works by destroying the rapidly dividing mutated cells, which impair their potential to divide further; the ionizing rays are directed very specifically to the targeting sites, which has made them a safer and much-favored approach to reducing or eliminating malignant growth.

Conversely, chemotherapy is a systemic approach where cytotoxic drugs are injected, which finally attack the cancer cells. Researchers are developing newer drugs and modalities to better tag cancerous cells to prevent harming the healthy ones. An entire field of epigenetics stands to realize that the incidence of tumors can be very well predicted at the embryonic stage, which might help in anticipating a disease that has plagued our world.

Conclusion:

Careful monitoring and the involvement of experienced specialists are important for the success of patients with ear, nose, and throat disorders. Patients are asymptomatic for a long time in the course of the disease. Tumors of the maxillary sinus are more common than those of the other sinuses. The common histology for the tumors is squamous cell carcinoma. Surgical resection followed by postoperative therapy is a cornerstone of treatment.