A benign tumor has an outer layer of cancerous cells beyond which are regular cells (I Think). The Tumor must have some kind of boundary layer like a wall where somehow the cancerous cells can't affect any more normal cells outside the wall. A Benign Tumor I think can be inactive for many months; it might never grow anymore. Might it be that the cancer cells at this Benign Tumor Wall are inhibited from affecting any more cells? Could there be an Apoptosis shut-off inhibitor or a cell-death pathway shutting-off inhibitor in this case?

  • $\begingroup$ Immune system fights cancer ... $\endgroup$
    – biogirl
    Commented May 6, 2014 at 7:25
  • $\begingroup$ Are inhibitors part of the immune system? $\endgroup$
    – user128932
    Commented May 8, 2014 at 7:14
  • $\begingroup$ There are some cells...I think NK cells..search NK cells on wikipedia $\endgroup$
    – biogirl
    Commented May 8, 2014 at 13:17

1 Answer 1


The primary difference between a benign tumor and a malignant tumor is that the former cannot metastasize; therefore they remain within the tissue boundaries.They grow slowly and are are not very de-differentiated thereby retaining some of the tissue organization.

Another point to be considered is that benign tumors do not cause vascularization (formation of blood vessels in the tumor tissue; triggered by secretion of VEGF), which also limits its growth.

  • 1
    $\begingroup$ I think the first part of your answer is more a definition than a mechanism. In addition, I thought benign tumors were bound within a certain structure that prevented them from growing out of control and from metastasis (I am definitely not an expert!) Perhaps a reference would be in place in your answer? $\endgroup$
    – AliceD
    Commented Dec 31, 2014 at 12:39
  • 1
    $\begingroup$ @ChrisStronks Yes it is a definition only. I cannot find a reference for the wall preventing its overgrowth. Metastasis happens because of a cellular differentiation event (such as EMT). It is not a wall that restricts the escape of the rogue cell. I need to add references, I am looking for a proper one. $\endgroup$
    Commented Dec 31, 2014 at 12:42
  • $\begingroup$ Does a benign tumor have some chemical or gene expression that blocks the secretion of VEGF? $\endgroup$
    – 201044
    Commented Mar 29, 2015 at 5:15
  • $\begingroup$ Is a benign tumour unable to metastasize because it can not cause vascularization (and then maybe there is no oncogenesis)?. Also does the apoptosis mechanisms in a benign tumour still 'work'? $\endgroup$
    – 201044
    Commented Nov 25, 2015 at 3:46
  • $\begingroup$ This is not entirely correct. A benign tumor is not cancer, for example, a skin tag. A malignant tumor is cancer, for example, astrocytoma. The distinction is not the ability to metastasize, though this does tend to be a characteristic of malignant (cancerous) tumors and not of benign (non cancerous) tumors. There are exceptions that can help clarify this. For example, most malignant CNS tumors do not metastasize. See Chapter 7 of Robbins and Cotran for these definitions. Malignant means cancer. Period. $\endgroup$
    – De Novo
    Commented Aug 24, 2018 at 8:16

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .