I am writing you an initial answer and than we can discuss it further, if you have further questions. You need to get the following investigations done (if not yet done);
1) Peripheral blood film
2) Urine and blood culture
3) Urine cytology
4) Renal nuclear scan
5) Colored doppler study of kidney, cyst and renal artery.
6) Renal agiography.
7) 24 hours total urinary protein.
8) MR urography
10) Autoimmune panel
These investigations should be able to give you the diagnosis.
Following are the diagnostic possibilities:
a) Sickle cell disease
b) Mild grade urinary tract infection
c) Tuberculosis of urinary tract
d) Glomerulonephritis autoimmune.
The kidney cyst is not very likely to be the causative as these are benign cyst. The colored doppler would rule out a complex cyst which has a more chance of malignancy.
It is privilege assisting you.
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