Follicular lymphoma is staged using the Ann Arbor staging system, which is typically used to stage all types of lymphomas. This system classifies the disease into four stages based on the extent and location of the tumor:
- Stage I: The cancer is located in a single lymph node region or a single non-lymph node site.
- Stage II: The cancer is located in two or more lymph node regions on the same side of the diaphragm, or the cancer has extended from a single lymph node region into a nearby organ.
- Stage III: The cancer is located in lymph node regions on both sides of the diaphragm.
- Stage IV: The cancer has spread widely into multiple tissues or organs.
Each stage can also be classified as "A" or "B". "A" means the patient does not have symptoms such as fever, weight loss, or night sweats. "B" means the patient has one or more of these symptoms.
Understanding the Classification of Follicular Lymphoma
Follicular lymphoma is classified based on the grade of the tumor, which is determined by the number of centroblasts (large cells) seen under a microscope in the tumor's follicles. The World Health Organization (WHO) classification system is commonly used:
- Grade 1: Fewer than 5 centroblasts per high power field (HPF).
- Grade 2: 6 to 15 centroblasts per HPF.
- Grade 3: More than 15 centroblasts per HPF. This grade is further divided into 3a (centrocytes are still present) and 3b (almost all cells are centroblasts).
It's important to note that the grade of follicular lymphoma doesn't always predict a patient's prognosis. Other factors, such as the patient's age, overall health, and specific genetic changes in the cancer cells, also play a role.
What are the Phases of Follicular Lymphoma?
The phases of follicular lymphoma are often referred to as "indolent" and "aggressive". Indolent follicular lymphoma grows slowly and may not require treatment for a long time. Aggressive follicular lymphoma grows more quickly and usually requires immediate treatment. The transition from indolent to aggressive phase is known as "transformation". This occurs in about 20-30% of patients and is often associated with a poorer prognosis.