My reaction is probably slightly different because my mother had this experience and the mole in question
was precancerous. She ended up having a few lymph nodes removed because of it.
Anyway, we know that Hannelore's anxiety and hypochondria can combine to serious effect. Remember the 'meningitis' mild stress headache? Trying to convince her that she
doesn't have The Big C will be difficult. Jeph hasn't really written Hannelore focus for a long time (the space arc was the last, IIRC). It will be interesting to see how he thinks the character has changed since then.
I'd go see a doc.
That would be the
sensible thing to do, yes. This is Hannelore we're dealing with and, when she's on full-power anxiety, she's not always as sensible as she could be.
[Edit]
FWIW, I'm wondering if, rather than focus on maybe being sick, Jeph will focus on how this brush with mortality affects Hannelore's thinking. Maybe she starts brooding about all the things that she hasn't done yet because she is letting her fears paralyse her. So she writes a "things to do before I die" list. Some are sweet ('Have a first kiss'), some are silly ('Eat a fantastically unhealthy but delicious meal') and some show her wilder side ('Learn to pole dance').
At one point she tells Marten and Faye that one of her undone things is to have a threesome with them roleplaying as her slaves. There is a panel of Marten and Faye doing their 'freak-out' faces before Hanners flees, weeping with laughter. The last panel is her ticking 'Prank Marten and Faye' on her list.