French to English Medical Medical (general) oral cancer

I am translating a text on oral cancer and would appreciate some feedback on the following. The term 'bourgeonnant' is used in two differents contexts.

a) carcinome épidermoïde végétant - Elle correspond à une masse bourgeonnante, développée sur une muqueuse congestive ......
b) forme ulcéro-infiltrante ou endophytique/carcinome épidermoïde endophytique, à fond bourgeonnant, inhomogène, saignant au moindre contact.

I have found a text from the University of Lyon which defines cancer bourgeonnant as; 'exophytique, induré, saignant facilement, pédicule large'. This clearly ties in with the first use (mass bourgeonnante) which I have provisionally translated as 'exophytic growth'.

However à fond bourgeonnant is applied to an invasive ulcerating endophytic tumour, could it refer to the proliferating invasive base of the tumour? I have provisionally translated this as 'with a proliferating base' (it clearly isn't exophytic).

I would be most grateful for any comments or suggestions for translating this term. My deadline unfortunately is tomorrow morning (5th Jan).

Thanks
Sue