Ann Arbor staging

Ann Arbor staging is a classification system used primarily to stage lymphoma, both Hodgkin's lymphoma and Non-Hodgkin's lymphoma. It was first introduced in 1971 at a meeting of the Cotswolds conference, held in Ann Arbor, Michigan, USA. The system provides a standard method for describing the extent of disease progression, which is crucial for prognosis and treatment planning.

Stages[edit | edit source]

The Ann Arbor staging system divides lymphoma into four stages:

Stage I: Involvement of a single lymph node region or a single extralymphatic organ or site.
Stage II: Involvement of two or more lymph node regions on the same side of the diaphragm.
Stage III: Involvement of lymph node regions on both sides of the diaphragm.
Stage IV: Diffuse or disseminated involvement of one or more extralymphatic organs or tissues, with or without associated lymph node involvement.

Substages[edit | edit source]

Each stage can be further divided into two substages:

A: No symptoms.
B: Presence of unexplained weight loss of more than 10% in the six months prior to diagnosis, unexplained fever with temperature above 38°C, or drenching night sweats.

Modifications[edit | edit source]

The Ann Arbor staging system has been modified over time to include additional information about the disease. The most notable modification is the Cotswolds modification, which adds an 'X' to denote bulky disease, defined as a mass greater than one-third the width of the chest or a nodal mass with a diameter greater than 10 cm.

Use in Clinical Practice[edit | edit source]

The Ann Arbor staging system is widely used in clinical practice and research. It helps clinicians to determine the most appropriate treatment and to predict patient outcomes. It is also used in clinical trials to ensure that study participants have similar disease characteristics.