Ulceration commonly happens in mouse subcutaneous tumour implant models. Different tumour lines have different ulceration potential, but in general the larger the tumour gets the more chance you have of ulceration. Tumours can expand all the way to the base of the epidermis, and likely damage or obstruct the blood vessels feeding the epidermis, leading to necrosis and subsequent ulceration.

Jean-Martin Lapointe

Dear Jean-Martin

Thanks a lot for your respond. So, ulceration does not make issue for immunotherapy treatment?(because of inflammation)

I think if you have ulceration, the mouse should be culled. It is a humane issue (ulcerations will get infected and can lead to sepsis), and additionally if you are looking at immune response within a tumour, ulceration will skew your results as the tissue underneath will be infiltrated by inflammatory cells reponding to tissue injury (rather than as a response to the tumour).