Cutaneous T-cell lymphoma (CTCL) is a group of non-Hodgkin lymphomas that primarily affect the skin. The staging and classification of CTCL are crucial for determining the appropriate treatment and predicting the patient's prognosis. The World Health Organization-European Organization for Research and Treatment of Cancer (WHO-EORTC) classification for cutaneous lymphomas is commonly used to classify CTCL. This classification system includes several types of CTCL, such as mycosis fungoides, Sézary syndrome, primary cutaneous CD30+ T-cell lymphoproliferative disorders, and others. Staging of CTCL is based on the TNMB system (Tumor, Node, Metastasis, Blood), which is a modification of the system used for other types of non-Hodgkin lymphoma. 1. Tumor (T): This describes the extent and spread of the primary tumor in the skin. It is divided into four stages (T1-T4) based on the percentage of the skin surface affected by patches, plaques, or tumors. 2. Node (N): This describes the extent of lymph node involvement. It is divided into four stages (N0-N3) based on whether the lymph nodes are clinically or pathologically involved and whether the involvement is regional or distant. 3. Metastasis (M): This describes the presence of metastasis to extracutaneous organs. It is divided into two stages (M0-M1) based on the absence or presence of extracutaneous disease. 4. Blood (B): This describes the involvement of malignant T-cells in the blood (Sézary cells). It is divided into two stages (B0-B2) based on the absence or presence and the amount of Sézary cells in the blood. The combination of these four parameters (TNMB) provides the overall stage of the disease, from stage I (early-stage disease) to stage IV (advanced disease). It's important to note that the prognosis of CTCL varies widely depending on the type and stage of the disease. For example, patients with early-stage mycosis fungoides often have a normal life expectancy, while those with advanced disease or other types of CTCL, such as Sézary syndrome, generally have a poorer prognosis. The staging and classification of CTCL are complex and require a thorough clinical evaluation, histopathological examination, and often additional tests such as imaging studies and blood tests. Therefore, they should be performed by a healthcare professional experienced in the management of CTCL.