pathology report conflict

[dinadonna]

the problem began when my father was congested for a long time due to seasonal flu
he went to many physicians and finally it was   "esphageal reflux" a year ago  and was cured
and congestion disappeared then he made by change lung x-ray it showed up fibrosis in certian part
and may be inflammation
or something else
, the physician took  a sample from the infected part
he went to a pathology lab and it said "lung carcinoma"
he went to a second pathology lab to confirm the report result of first one
but the second  lab said "no viable tumour tissue presented" !
the two report conclusions were agreed that  fibrosis and inflammation are shown
the physician recommended to perform PET scan which will  give us which path of treatment to follow
the PET scan report said that max SUV  value recorded was 6.6 and it said that "inflammation
was slightly favoured however taking sample and tested in a lab is recommended"
knowing that  my father doesn't  have any pain or feel exhausted, he perform his daily day routine normally
please need advice we are so scared and confused and just wonder how pathology labs
gives different results in something crucial?!