I think it would be even less likely for kidney to be the *only* site of
metastasis, so the doctor's response is understandable, even if he does
not share the faith of some in early mammograms.  But it is of course
perfectly possible for breast cancer patients to simultaneously get some
other kidney disease, or even, heaven forbid, primary renal cancer.  In
the first instance the problem is to diagnose the cause of the symptoms,
if there does turn out to be a tumour there, finding its source is
pretty academic.  Either case is unlikely but possible.

Tim Jackson

The kidneys form when blood vessels in the middle layer of tissue in a very
early embryo form capillary tufts and a dimple in the internal layer (I
think--might be the external layer) grows toward it,branching out to
surround each tuft.  The process works most of the time, an amazing feat
considering the enormous numbers of tufts and ducts that have to get
together, but sometimes the hookup does not go right, and one or more cysts
form inthe kidney.  They are very common and rarely are a source of trouble.
There is a condition called polycystic kidney where lots of cysts form and
kidney failure eventuallly occurs, but that is not your situation.

Low creatinine does not herald any kidney disease that I am aware of.  It
may mean you have low muscle mass.  Creatinine is produced mostly in muscles
and excreted by the kidneys.  It is not actively excreted nor actively
reabsorbed, so the amount going out is proportional to the serum
concentration and the glomerular filtration rate--the number of mL of
potential urine formed each minute in the upper part of the kidney.  Low
serum creatinine could occur if the production rate were low, but getting a
filtration rate high enough to bring it down would (1) be almost impossible
and (2) I am unaware of any disease associated with high filtration.  Worry
about creatinine only if it is high.

The symptoms of frequency and urgency usually are associated with irritation
in the lower urinary tract, and that is usually associated with infection,
but a urinalysis should show that easily.  I would not expect growth of a
cancer in the kidney to release anything into the urine that would cause
irritation.  That is one of the problems with primary cancer of the kidney;
they tend to be silent until quite large.  I don't know what the problem is,
but cancer would not be high on my list of suspects.

I don't care IF my lump didn't have cancer......It was removed.  I
didn't have to keep it....didn't give it a chance to be cancer .....it
was OUTTA THERE...... period...... end of discussion

I agreee --some doctors  are jerks----or plain idiots and stupid!

Bonnie

The darn doctor may be right this time.
A met in the kidney is very rare, cysts are very common and are easy to
recognise in ultrasound.
If you're still worried, check your markers (CEA and CA-15.3 or CA27/29)
and if they're above normal go for a CT of the whole abdomen. Or have it
done even if they're normal if it will give you peace of mind and to
rule out other problems.