[Histonet] Contamination..processor?

[tigger13b <@t> aol.com]

Hello everyone.

     Today we have a problem with contamination.  The pathologist notes cells from tonsil specimens here and there on our GI biopsy slides.  The cells are in the block.  I'm trying to ascertain the source of the contamination.  
     The grossing pathologist grossed the tonsils AFTER all GI specimens yesterday (not source of contaminant).  We (the techs) embedded all GI specimens first, trimmed, cut, floated and stained ALL GI specimens BEFORE the tonsils (not source of contaminant).  The only other source of the contamination I can think of is from the tissue processor.  We have a Tissue Tek VIP closed processor.  Has anyone ever experienced any problems like this?  We had a similar issue a few weeks ago.  I thought the contaminant cells may be from a bladder tumor, which had multiple sections submitted.  In this instance the cells showed up days work of the bladder tumor, and in the following days work also (though the pathologists could not say for sure the cells were from the bladder case).  We changed our formalin solutions in the processor and the problem did not present the next day.  We also started putting all bladder tumor specimens in the microcassettes, to prevent tissue from escaping.  Has anyone had any problem like this, or does anyone have any ideas on how to prevent this in the future?  We had not seen this problem until these past two incidences, and this tonsil problem is particularly strange to me because we process tonsils and GI specimens in the same workload on a regular basis and have never had this issue before.  Any help is appreciated!  

Thanks!
Brandi