A patient with whole body fatigue, fever/chills, and cachexia should be evaluated for which lymphoma?

The presentation of whole body fatigue, fever/chills, and cachexia is highly suggestive of Hodgkin's lymphoma. This type of lymphoma often manifests with "B symptoms," which include fever, night sweats, and weight loss (cachexia). These symptoms are indicative of a systemic reaction to the malignancy and are crucial for diagnosis and staging of Hodgkin's lymphoma.

Hodgkin's lymphoma can present with lymphadenopathy as well, but the systemic symptoms can be quite pronounced, leading to significant cachexia and fatigue, as seen in this patient. The combination of these symptoms points towards an aggressive lymphoproliferative disorder that warrants urgent evaluation.

In contrast, lung cancer and diabetes may produce some overlapping symptoms such as fatigue, but they do not typically present with the classic B symptoms associated with Hodgkin's lymphoma. B-cell leukemia is a consideration, but the specific combination of systemic symptoms in the question is more characteristic of Hodgkin's rather than leukemia, which also has different primary presenting symptoms.