Kathleen Bruce wants to know about lump behind areola.  This could indeed be
an abscess without fever.  Periareolar abscesses are not that uncommon --
even in the early postpartum, and if they wall off quickly, may not for some
time generate systemic sx. Some pathologists believe these are a bacterial
form of duct extasia.  The basic pathological change begins with squamous
metaplasia of the lining of one or more of the major nipple ducts with
obstruction of the duct by keratin plugs.  The ducts rupture, followed by
bacterial invasion.

 Also, could be a galactocele -- ie a sterile, milk filled abscess.  The
oozy yellow stuff could be pus, could be secretions from other ducts getting
rather jammed up behind the obstruction (I read recently that ducts were
discovered to intertwine, not just to converge.)  An ultrasound would be
able to accurately visualize the nature of the lump (i.e. solid or cystic)
for diagnostic purposes.
 Duct ectasia (plasma cell mastitis) is an inflammatory lesion that accounts
for 1% of all operative breast lesions.  It is centrally located, and
initiated by an intraductal secretion of fatty acids with dilatation and
rupture of the major ducts. It produces a kind of "chemical mastitis" with a
toothpaste like material often seen oozing from these ducts.  It can cause
the nipple to retract (one of the warning signs of carcinoma) and as needle
biopsy is often inconclusive, there is usually excision of the mass.
Unfortunately, this being right behind the nipple makes this very invasive
surgery.

I pulled this info from several sources, but a really excellent source is a
recent Medscape article by R. Steyskal, Minimizing the Risk of Delayed
Diagnosis of Breast Cancer.  Keywords, breast cancer, malpractice,
mammogram, cancer screening.
Hope this helps.
Barbara