Difference between cyst and a swollen lymph node?

Unclear question: Cyst is a fluid filled structure and a swollen lymph node may be enlarged due to physiologic response to infections or may be enlarged due to cancer. It may not be feasible to know which one it is just by palpation.

Different: A swollen lymph gland represents alteration in the gland such as inflammation or malignancy that causes the normal sized gland to expand so that it becomes palpable. A cyst is a functional secretory structure that produces fluid which becomes encapsulated. As such a sebaceous gland that overproduces forms a sebaceous cyst. An obstructed milk duct in breast fills with fluid to form a cyst.

Need to examine: It is not feasible to tell without examination and may require removing the lesion.