Lymphoma is generally not hereditary, as it is not a genetic disease. However, I must mention that most neoplastic diseases do have some hereditary factors to some extent. The reason for this is that the cause of lymphoma is currently unclear, and it may be related to genetic mutations, which raises the issue of heredity. Another point is that heredity often refers to transmission among direct relatives. This means there could be a problem in that you might share similar environments and lifestyles, including diet. If there are factors in your diet or living environment that could trigger lymphoma, and you are both exposed to these factors, then your probability of developing lymphoma could indeed be higher than in patients without a family history, leading to such a concern.