The stage of a lymphoma helps predict a patients prognosis and is used to help select the appropriate therapy.The Ann Arbor staging system is routinely used for staging of both HL and NHL. In this staging system, stage I represents localized disease contained within a lymph node group, II represents the presence of lymphoma in two or more lymph nodes groups, III represents spread of the lymphoma to lymph nodes groups on both sides of the diaphragm, and IV indicates spread to tissue outside the lymphatic system. Different suffixes imply the involvement of different organs, for example, S for the spleen and H for the liver. Extra-lymphatic involvement is expressed with the letter E. In addition, the presence of B symptoms (one or more of the following: unintentional loss of 10% body weight in the last 6 months, night sweats, or persistent fever of 38 °C or more) or their absence is expressed with B or A, respectively.CT scan or PET scan imaging modalities are used to stage cancer. PET scanning is advised for fluorodeoxyglucose-avid lymphomas, such as Hodgkin lymphoma, as a staging tool that can even replace bone marrow biopsy. For other lymphomas, CT scanning is recommended for staging.Age and poor performance status are other established poor prognostic factors. This means that people who are elderly or too sick to take care of themselves are more likely to die from lymphoma than others.
This examination reveals histopathological features that may indicate lymphoma. After lymphoma is diagnosed, a variety of tests may be carried out to look for specific features characteristic of different types of lymphoma. These include:

Immunophenotyping
Flow cytometry
Fluorescence in situ hybridization testing

Classification
According to the World Health Organization (WHO), lymphoma classification should reflect in which lymphocyte population the neoplasm arises. Thus, neoplasms that arise from precursor lymphoid cells are distinguished from those that arise from mature lymphoid cells. Most mature lymphoid neoplasms comprise the non-Hodgkin lymphomas. Historically, mature histiocytic and dendritic cell (HDC) neoplasms have been considered mature lymphoid neoplasms, since these often involve lymphoid tissue.Lymphoma can also spread to the central nervous system, often around the brain in the meninges, known as lymphomatous meningitis (LM). Hodgkin lymphoma
Hodgkin lymphoma accounts for about 15% of lymphomas. It differs from other forms of lymphomas in its prognosis and several pathological characteristics. A division into Hodgkin and non-Hodgkin lymphomas is used in several of the older classification systems. A Hodgkin lymphoma is marked by the presence of a type of cell called the Reed–Sternberg cell. Non-Hodgkin lymphomas
Non-Hodgkin lymphomas, which are defined as being all lymphomas except Hodgkin lymphoma, are more common than Hodgkin lymphoma. A wide variety of lymphomas are in this class, and the causes, the types of cells involved, and the prognoses vary by type. The number of cases per year of non-Hodgkin lymphoma increases with age. It is further divided into several subtypes.