Is it permissible to conceal the symptoms of a disease or tumor from a suitor, or to refuse a medical examination for fear of not getting married?

There is no obligation to inform the suitor about a disease that does not affect enjoyment, and there is no harm in concealing it and conducting the examination after marriage. In fact, concealment might be preferable.

It is permissible to conceal a benign tumor that has been removed, or a tumor that does not affect enjoyment, and it is better not to disclose it to avoid unwarranted apprehension.

There is no harm in not undergoing an examination unless there are indications suggesting a possible infection. If such indications exist, early examination is better for treatment. It is advisable to rely on Allah and not be preoccupied with something that doctors have stated does not exist.