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Stages of Mycosis Fungoides (Including Sézary Syndrome)

After mycosis fungoides and Sézary syndrome have been diagnosed, tests are done to find out if cancer cells have spread from the skin to other parts of the body.

The process used to find out if cancer has spread from the skin 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 procedures may be used in the staging process:

  • 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.
  • CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, such as the lymph nodes, chest, abdomen, and pelvis, 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.
  • 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.
  • Lymph node biopsy: The removal of all or part of a lymph node. A pathologist views the lymph node tissue under a microscope to check for cancer cells.
  • Bone marrow aspiration and biopsy: The removal of bone marrow and a small piece of bone by inserting a hollow needle into the hipbone or breastbone. A pathologist views the bone marrow and bone under a microscope to look for signs of cancer.

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 mycosis fungoides spreads to the liver, the cancer cells in the liver are actually mycosis fungoides cells. The disease is metastatic mycosis fungoides, not liver cancer.

The following stages are used for mycosis fungoides and Sézary syndrome:

Stage I Mycosis Fungoides

Stage I is divided into stages IA and IB as follows:

  • Stage IA: Patches, papules, and/or plaques cover less than 10% of the skin surface.
  • Stage IB: Patches, papules, and/or plaques cover 10% or more of the skin surface.

There may be a low number of Sézary cells in the blood.

Stage II Mycosis Fungoides

Stage II is divided into stages IIA and IIB as follows:

  • Stage IIA: Patches, papules, and/or plaques cover any amount of skin surface. Lymph nodes are abnormal, but they are not cancerous.
  • Stage IIB: One or more tumors that are 1 centimeter or larger are found on the skin. Lymph nodes may be abnormal, but they are not cancerous.

There may be a low number of Sézary cells in the blood.

Stage III Mycosis Fungoides

In stage III, 80% or more of the skin surface is reddened and may have patches, papules, plaques, or tumors. Lymph nodes may be abnormal, but they are not cancerous.

There may be a low number of Sézary cells in the blood.

Stage IV Mycosis Fungoides/Sézary Syndrome

When there is a high number of Sézary cells in the blood, the disease is called Sézary syndrome.

Stage IV is divided into stages IVA1, IVA2, and IVB as follows:

  • Stage IVA1: Patches, papules, plaques, or tumors may cover any amount of the skin surface, and 80% or more of the skin surface may be reddened. The lymph nodes may be abnormal, but they are not cancerous. There is a high number of Sézary cells in the blood.
  • Stage IVA2: Patches, papules, plaques, or tumors may cover any amount of the skin surface, and 80% or more of the skin surface may be reddened. The lymph nodes are very abnormal, or cancer has formed in the lymph nodes. There may be a high number of Sézary cells in the blood.
  • Stage IVB: Cancer has spread to other organs in the body, such as the spleen or liver. Patches, papules, plaques, or tumors may cover any amount of the skin surface, and 80% or more of the skin surface may be reddened. The lymph nodes may be abnormal or cancerous. There may be a high number of Sézary cells in the blood.

Mycosis fungoides and Sézary syndrome can recur (come back) after they have been treated.

Mycosis fungoides and Sézary syndrome may come back in the skin or in other parts of the body, such as the spleen or liver.

This information is not intended to replace the advice of a doctor. Navigating Care disclaims any liability for the decisions you make based on this information. This information was sourced and adapted from Adapted from the National Cancer Institute's Physician Data Query (PDQ®) Cancer Information Summaries on www.cancer.gov.