Local Invasion: Benign or Malignant?

Assalamualaikum.. just want to share this, in case any of us had had similar confusion.. ^_^'

A question was asked to Dr Norlelawati to get a clearer explanation on 'local invasion'..

Question:

My friends & i remembered that u said in the lecture, local invasion refers to benign tumor. U also stated about that clearly in the notes on 'tumor invasion & metastasis' u gave us.

My question is why is it stated in Robin 8th edition:

    page 179 "Next to the development of metastases, local invasiveness is the most reliable feature that distinguishes malignant from benign tumors"

    page 181 in the summary "Benign tumors remain localized to the site of origin, whereas malignant tumors are locally invasive and they metastasize to distant site"

Could you please explain what do the Robin's sentences actually mean?

Answer given by Dr Norlela:

the confusion is rather due to terminology that we/ I use...some author would like to refer to the term i.e "local invasion"  when referring to benign growth.  As being stressed during my lecture, for growth of malignant tumour, before it  metastasis to other site, the tumour cells  in fact , need to invade the surrounding structure....this is also called invasion or  " local invasiveness" - robbins....in "local invasiveness" as explained by robbins, it tumour carries all the characteristic features  of malignant tissue; not encapsulated, breaching the basement membrane, and the cell it self is malignant cell -cellular n nuclear polymorphism etc bla bla....whereas where we talking about benign tumour remember,.......there are encapsulated , but they will grow and expand within that capsule st pressing the surrounding normal structure ( this  is st called  local invasion by certain author where i refer to when preparing the lecture).

NOW
if these  are making you confused -  stick to common terminology use by Robbins ( the  kitab of Pathology).  Nevertheless you must first understand what the  biological and physical activity that are going on that defer  benign fr malignant tumour.    Conclusion: malignant cells has the capability to invade ( invasiveness) and to metastasis ( as explain in my lecture).  Cheers.

dr lela

That's all.. wallahua'lam..