Dear  all, please help.

We have come across this strange pigment in a bladder biopsy from a patient
whose bladder appears black on cystoscopy.  Initial diagnosis was melanosis,
but this clearly is not.  The pigment is blue-black on unstained sections
and forms small fibres and needle-like crystals.  It is briefringent.  X-ray
dispersion analysis identified carbon and oxygen - suggesting an organic
compound.  Furthermore, on the first attempt at EDAX, the EM technician used
the original slide and upon soaking in xylene for 2 days, the pigment
dissolved.

Can anyone suggest what the pigment may be, or any methods we could use to
identify it.

I have a digital image which I would gladly e-mail to anyone requesting one
(picture/1000 words and all that).


Hope you can help

thanks, Neal.