Peripheral T-cell lymphoma (PTCL) is a rare and aggressive type of non-Hodgkin lymphoma (NHL). About 10-15% of NHL patients develop a T-cell lymphoma subtype. People over 60 years old are usually the ones who get affected by this type of cancer. Diagnosis of this cancer is more common in men than women. But, it does not imply that young adults, or even children, for that matter, can not develop peripheral T-cell lymphoma. However slim the chances may be.