Which condition can cause lymph nodes to be matted together?

Matted lymph nodes are a clinical finding that often indicates a more serious underlying condition, such as lymphoma. In this context, when lymph nodes become matted, it means they are no longer distinct entities but rather fused together, which is commonly associated with malignancies like lymphoma.

Lymphoma can cause the lymphatic tissue to become infiltrated with cancerous cells, leading to the enlargement and coalescence of lymph nodes. This alteration signifies an abnormal immune response due to the presence of neoplastic cells, as opposed to the normal separation seen in typical lymphadenopathy caused by infections or benign conditions.

In contrast, conditions like influenza or acute inflammatory processes often result in enlarged lymph nodes that remain distinct and freely movable, and a normal immune response will promote lymph node activity without this coalescence. As a result, the distinct nature and presentation of the lymph nodes in lymphoma compared to other conditions highlight why lymphoma is the correct answer in this scenario.