Final answer:
Enlarged lymph nodes can be associated with various conditions, including infections and lymphoma. Metastatic malignancy can cause lymph node enlargement but is not the exclusive cause and is not a likely cause in the absence of other symptoms. A lymph node biopsy is essential for diagnosis in persistent cases.
Step-by-step explanation:
Enlarged lymph nodes are commonly found in several medical conditions, including infections, immune responses to foreign bodies, and cancers like lymphoma. However, these swollen nodes are not exclusively indicative of a metastatic malignancy. Metastatic malignancy refers to cancer that has spread from its original site to other parts of the body, which may include lymph nodes. Yet, in the context of the question, it is not the condition excluded from being associated with enlarged lymph nodes. Lymph node enlargement is more likely linked to benign conditions, especially infections, rather than malignancy. Therefore, while metastatic malignancy can cause swollen lymph nodes, it is not the only or most common explanation for this symptom.
An example that illustrates the broader causes of swollen lymph nodes is Wei's case from the provided reference. Initially, Wei's doctor suspected a viral or bacterial infection because these are standard causes of node enlargement in young individuals. After Wei's condition did not improve with antibiotics and other symptoms persisted, a biopsy confirmed lymphoma. This illustrates that while infections are common causes of swollen lymph nodes, other serious conditions like cancer must also be considered if the nodes remain enlarged over time and other symptoms are present.