The Marfan syndrome is classified as a heritable disorder of connective tissue whose pathogenetic mechanism has not yet been defined. An inborn error of protein metabolism, particularly in collagen has long been hypothesized, but conclusive evidence on the matter is not available. It is usually diagnosed in young patients and can be associated with other disease. We report a case of an unusual association with a malignant non-Hodgkin lymphoma in a 55-year-old patient, never described before.