What malignant tumor originates in lymphatic tissue?

Lymphoma is the correct answer because it specifically refers to a type of cancer that arises from lymphatic tissue, which includes lymph nodes, the spleen, and other tissues involved in the immune response. There are various forms of lymphoma, including Hodgkin lymphoma and non-Hodgkin lymphoma, characterized by the uncontrolled proliferation of lymphocytes, a type of white blood cell crucial for fighting infections. This differentiation is important in oncology, as lymphoma is distinct from other cancer types and involves a unique pathology and treatment approach.

In contrast, leukemia, although also a malignancy of blood cells, originates in the bone marrow and affects the blood and marrow rather than the lymphatic tissues. Lymphadenitis refers to inflammation of the lymph nodes, usually due to infection, rather than cancer. Influenza, a viral infection, has no connection to tumor formation or lymphatic tissue malignancies. Thus, lymphoma is clearly defined as a malignant tumor that originates specifically in lymphatic tissue.