Confused on pathology dx. Went from NSCLC to Pancreatobillary???

My Dad was very active riding his bike 7-10 miles a day and was sent for routine bloodwork.  Some liver enzymes were raised and to make a really long story short he was given a liver biopsy and the original path came back NSCLC lung cancer.  It was sent to Sloane Kettering and they looked at it and said (briefly) postive CK7 and negative CK20, CDX2, TTF1 and Hepar Based on morph and immunophen findings. They favor the tumor to be pancreatobillary or upper GI.  Mod Differentiated Adenocarcinoma involving extensively scierotic stroma. moderately atyplical nuclei and arranged in nests with some gladular formation.  Everything I see on internet indicated that GI tumors are 95% of the time CDX2 positive.  I am so confused, can you please tell me what they may be seeing that favors GI over the original pathologist's NSCLC dx.  The orginal pathologist was the one who sent the slides to Sloane Kettering.  Thank you for any info that you can provide.  By the way, all tests CT, Colonoscopy, ERCP, and Endo show NO primary tumor anywhere. Also, he is having no symptoms of anything.  Again thank you so much for your help.

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I thought this was posting to the expert forum.  I guess that forum is no longer accepting questions???  But, if anyone has had an experience like this, I would appreciate any response.  Thank You.