This is a medical question of type : stages 
 What are the stages of Paranasal Sinus and Nasal Cavity Cancer ? 
 Key Points
                    - After paranasal sinus and nasal cavity cancer has been diagnosed, tests are done to find out if cancer cells have spread within the paranasal sinuses and nasal cavity or to other parts of the body.     - There are three ways that cancer spreads in the body.    - Cancer may spread from where it began to other parts of the body.    - There is no standard staging system for cancer of the sphenoid and frontal sinuses.    - The following stages are used for maxillary sinus cancer:         - Stage 0 (Carcinoma in Situ)     - Stage I     - Stage II     - Stage III     - Stage IV        - The following stages are used for nasal cavity and ethmoid sinus cancer:         - Stage 0 (Carcinoma in Situ)     - Stage I     - Stage II     - Stage III     - Stage IV
                
                
                    After paranasal sinus and nasal cavity cancer has been diagnosed, tests are done to find out if cancer cells have spread within the paranasal sinuses and nasal cavity or to other parts of the body.
                    The process used to find out if cancer has spread within the paranasal sinuses and nasal cavity or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the stage in order to plan treatment. The following tests and procedures may be used in the staging process:         -   Endoscopy : A procedure to look at organs and tissues inside the body to check for abnormal areas. An endoscope is inserted through an opening in the body, such as the nose or mouth. An endoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue or lymph node samples, which are checked under a microscope for signs of disease.    -   CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.    -   Chest x-ray : An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.    -   MRI (magnetic resonance imaging) with gadolinium : A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. Sometimes a substance called gadolinium is injected into a vein. The gadolinium collects around the cancer cells so they show up brighter in the picture. This procedure is also called nuclear magnetic resonance imaging (NMRI).    -   PET scan (positron emission tomography scan): A procedure to find malignant tumor cells in the body. A small amount of radioactive glucose (sugar) is injected into a vein. The PET scanner rotates around the body and makes a picture of where glucose is being used in the body. Malignant tumor cells show up brighter in the picture because they are more active and take up more glucose than normal cells do.     -   Bone scan : A procedure to check if there are rapidly dividing cells, such as cancer cells, in the bone. A very small amount of radioactive material is injected into a vein and travels through the bloodstream. The radioactive material collects in the bones and is detected by a scanner.
                
                
                    There are three ways that cancer spreads in the body.
                    Cancer can spread through tissue, the lymph system, and the blood:         - Tissue. The cancer spreads from where it began by growing into nearby areas.     - Lymph system. The cancer spreads from where it began by getting into the lymph system. The cancer travels through the lymph vessels to other parts of the body.     - Blood. The cancer spreads from where it began by getting into the blood. The cancer travels through the blood vessels to other parts of the body.
                
                
                    Cancer may spread from where it began to other parts of the body.
                    When cancer spreads to another part of the body, it is called metastasis. Cancer cells break away from where they began (the primary tumor) and travel through the lymph system or blood.         - Lymph system. The cancer gets into the lymph system, travels through the lymph vessels, and forms a tumor (metastatic tumor) in another part of the body.    - Blood. The cancer gets into the blood, travels through the blood vessels, and forms a tumor (metastatic tumor) in another part of the body.        The metastatic tumor is the same type of cancer as the primary tumor. For example, if nasal cavity cancer spreads to the lung, the cancer cells in the lung are actually nasal cavity cancer cells. The disease is metastatic nasal cavity cancer, not lung cancer.
                
                
                    There is no standard staging system for cancer of the sphenoid and frontal sinuses.
                    
                
                
                    The following stages are used for maxillary sinus cancer:
                    Stage 0 (Carcinoma in Situ)    In stage 0, abnormal cells are found in the innermost lining of the maxillary sinus. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ.       Stage I     In stage I, cancer has formed in the mucous membranes of the maxillary sinus.       Stage II     In stage II, cancer has spread to bone around the maxillary sinus, including the roof of the mouth and the nose, but not to bone at the back of the maxillary sinus or the base of the skull.       Stage III    In stage III, cancer has spread to any of the following:            - Bone at the back of the maxillary sinus.     -  Tissues under the skin.     - The eye socket.     - The base of the skull.     - The ethmoid sinuses.            or      Cancer has spread to one lymph node on the same side of the neck as the cancer and the lymph node is 3 centimeters or smaller. Cancer has also spread to any of the following:            - The lining of the maxillary sinus.     - Bones around the maxillary sinus, including the roof of the mouth and the nose.     - Tissues under the skin.     - The eye socket.      - The base of the skull.     - The ethmoid sinuses.              Stage IV     Stage IV is divided into stage IVA, IVB, and IVC.         Stage IVA      In stage IVA, cancer has spread:               - to one lymph node on the same side of the neck as the cancer and the lymph node is larger than 3 centimeters but not larger than 6 centimeters; or      - to more than one lymph node on the same side of the neck as the original tumor and the lymph nodes are not larger than 6 centimeters; or      -  to lymph nodes on the opposite side of the neck as the original tumor or on both sides of the neck, and the lymph nodes are not larger than 6 centimeters.               and cancer has spread to any of the following:               - The lining of the maxillary sinus.      - Bones around the maxillary sinus, including the roof of the mouth and the nose.       -  Tissues under the skin.      - The eye socket.      - The base of the skull.      - The ethmoid sinuses.               or       Cancer has spread to any of the following:               - The front of the eye.       - The skin of the cheek.      - The base of the skull.      - Behind the jaw.      - The bone between the eyes.      - The sphenoid or frontal sinuses.              and cancer may also have spread to one or more lymph nodes 6 centimeters or smaller, anywhere in the neck.            Stage IVB      In stage IVB, cancer has spread to any of the following:               - The back of the eye.      - The brain.      - The middle parts of the skull.      - The nerves in the head that go to the brain.      - The upper part of the throat behind the nose.      - The base of the skull.              and cancer may be found in one or more lymph nodes of any size, anywhere in the neck.      or      Cancer is found in a lymph node larger than 6 centimeters. Cancer may also be found anywhere in or near the maxillary sinus.            Stage IVC       In stage IVC, cancer may be anywhere in or near the maxillary sinus, may have spread to lymph nodes, and has spread to organs far away from the maxillary sinus, such as the lungs.
                
                
                    The following stages are used for nasal cavity and ethmoid sinus cancer:
                    Stage 0 (Carcinoma in Situ)    In stage 0, abnormal cells are found in the innermost lining of the nasal cavity or ethmoid sinus. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ.       Stage I     In stage I, cancer has formed and is found in only one area (of either the nasal cavity or the ethmoid sinus) and may have spread into bone.       Stage II     In stage II, cancer is found in two areas (of either the nasal cavity or the ethmoid sinus) that are near each other or has spread to an area next to the sinuses. Cancer may also have spread into bone.       Stage III     In stage III, cancer has spread to any of the following:            - The eye socket.     - The maxillary sinus.     - The roof of the mouth.     - The bone between the eyes.            or      Cancer has spread to one lymph node on the same side of the neck as the cancer and the lymph node is 3 centimeters or smaller. Cancer has also spread to any of the following:            - The nasal cavity.     - The ethmoid sinus.     - The eye socket.     - The maxillary sinus.     - The roof of the mouth.     - The bone between the eyes.              Stage IV     Stage IV is divided into stage IVA, IVB, and IVC.         Stage IVA      In stage IVA, cancer has spread:               - to one lymph node on the same side of the neck as the cancer and the lymph node is larger than 3 centimeters but not larger than 6 centimeters; or      - to more than one lymph node on the same side of the neck as the original tumor and the lymph nodes are not larger than 6 centimeters; or      -  to lymph nodes on the opposite side of the neck as the original tumor or on both sides of the neck, and the lymph nodes are not larger than 6 centimeters.               and cancer has spread to any of the following:               - The nasal cavity.      - The ethmoid sinus.      - The eye socket.      - The maxillary sinus.      - The roof of the mouth.      - The bone between the eyes.               or      Cancer has spread to any of the following:                - The front of the eye.      - The skin of the nose or cheek.      - Front parts of the skull.      - The base of the skull.      - The sphenoid or frontal sinuses.              and cancer may have spread to one or more lymph nodes 6 centimeters or smaller, anywhere in the neck.            Stage IVB      In stage IVB, cancer has spread to any of the following:                - The back of the eye.      - The brain.      - The middle parts of the skull.      - The nerves in the head that go to the brain.      - The upper part of the throat behind the nose.      - The base of the skull.              and cancer may be found in one or more lymph nodes of any size, anywhere in the neck.      or       Cancer is found in a lymph node larger than 6 centimeters. Cancer may also be found anywhere in or near the nasal cavity and ethmoid sinus.            Stage IVC      In stage IVC, cancer may be anywhere in or near the nasal cavity and ethmoid sinus, may have spread to lymph nodes, and has spread to organs far away from the nasal cavity and ethmoid sinus, such as the lungs.