is less common than Non-Hodgkin lymphoma (NHL) and is characterized by the presence of Reed-Sternberg cells seen under microscopy. HL essentially develops in a localized chain of lymph nodes. The cervical lymphatic chain is frequently involved (neck nodes), although it can also develop in the mesenteric and paraaortic chains. It spreads contiguously (from one node to another, or to adjacent tissues) and rarely involves extra-nodal sites. HL also has a bimodal age distribution, generally differentiated into peak age groups of 15 to 34 years old, and those over 50 years.