Peripheral T-Cell Lymphoma (PTCL) is a type of cancer that originates in the T-cells, which are a crucial part of the immune system. This lymphoma affects the peripheral lymphatic system, including lymph nodes and other tissues outside the bone marrow. PTCL is considered aggressive and can vary in its symptoms, often leading to swollen lymph nodes, fever, and weight loss. There are several subtypes of PTCL, each with distinct characteristics and treatment approaches. Diagnosis typically involves a combination of biopsy, imaging tests, and blood tests. Treatment options may include chemotherapy, radiation therapy, and sometimes stem cell transplants, depending on the specific subtype and stage of the disease.