Lump under armpit

My sister noticed a small lump under her armpit several months ago. She had her doc look at it, she felt it and said its a cyst. That was that. Now last night, it started becoming painful, and she felt it and she said it was larger. Its under her skin inside. Anyone ever have this? Shes nervous its cancer, but I read cancer lumps under the armpit are typically painless. She is calling a dermatologist in the morning to have it either looked at or biopsied. Any experience with this?

This page is a permanent link to the reply below and its nested replies. See all post replies »

canusernamebemyusername · M

The armpit is a great place for cysts to form due to moisture and friction. If it has swollen up over night then it is filling with blood/pus and the doctor may lance it to drain it.

Coralmist · 41-45, F

@canusernamebemyusername Its inside the armpit, not on the armpit. She thinks it might be lymph node that enlarged but unsure 😞