I have a lump about the size of a pea on my sternum between my breast.  I noticed it in Oct but it has grown some in the last few weeks.  It is tender, but I think a lot of the tenderness is because I am constantly messing with it.  It is hard (but not bone hard) and it does not move.  It feels like it is attached to my sternum.  It did develop kinda like a pimple over the lump that had white liquid (smelly) drain from it.  I have an appt with my doctor next week, but really concerned.
Thanks for your question on Chat Doctor. I can understand your concern. By your history and description, possibility of infected sebaceous cyst is more likely. And the liquid you are talking about it nothing but sebum (infected material of cyst). It is common in anterior chest. Best treatment is complete removal of cyst. This will prevent recurrence. So better to consult doctor and discuss need for incision and Chat Doctor. Also rule out diabetes as this kind of infection is common in diabetic. Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.