As a 25 year survivor of non Hodgkin's lymphoma, (likely a cascade event form exposure to defoliants) I can tell you that there are multiple other symptoms besides an enlarged painless node that accompany lymphatic cancers. You know well before you have some surface nodal presentation (most of them are buried deep within you) that you are genuinely sick. Since this forum is and oral cancer forum I won't go through the list.
What we are talking about here are oral cancers, and specifically why in some people who have SCC in their lymph nodes after a fine needle aspiration and biopsy, (obviously from the mouth or throat where squamous cells reside), have no visual presentation of the disease in their mouths that we would normally see in tobacco oral carcinogenisis. No one has said here that a lymph node is ever a primary in oral cancers, and for that matter in most other cancers, as it is a central collection point of metastasis - your lymphatic system is part of your immune system trying to clear things from your body ranging from the detritus of infections to cancer.
Breast cancer patients have regional spread to lymph node under their arm pits and in their thorax, testicular and prostate cancer patients have spread to the nodes in the groin etc., because the lymph system is trying to do it's job. So if you go back and read the original posting, the statement was in relation to the question was why oral cancers can sometimes be occult and show up as a cervical node first find even though that is never the primary; not the multiple reasons a lymph node might be cancerous.
By the by, a lymph dissection and biopsy for a suspect lymphoma cancer will always find lymphoid cells in the node, as that is what it is made from - just in lymphoma some of those cells which are there will have the cellular change that make then cancerous lymph cells vs. normal lymph cells. This is a cascade of a disease that is primarily composed of malignant lymphocytes. Lymphocytes are a normally occurring part of the white blood cell series, all part of your immune defensive system.
