Lesion on liver

[Alan-S-Mamen]

  In July 1998, a CT scan showed a 1 cm lesion on my liver. Several doctors have been unable to identify the reason.
  1.) I was taking high doses of Niacin daily for ten years to treat high tri-glycerides.
  2.) In May 1997, the Niacin was changed to a prescription for Lopid (an inappropriate move as now my cholesterol is too low and tri-glycerides are way too high again.
  3.) In Nov & Dec of 1997 I had chemo and radiation to reduce a lung cancer tumor.
  4.) In Jan 1998 my left lung was removed.
  5.) In April 1998 a surgery follow-up CT-scan and blood test both indicated normal healing.
  6.) In July 1998 a surgery follow-up CT-scan showed the 1 cm lesion, but the blood test showed no liver abnormality.
  The lesion appeared on my liver for the first time in July. I had a follow-up Sonogram and MRI which have apparently ruled out several ailments, but ruled in nothing. I had an AMAS blood test which came back normal, indicating no cancer in my body.
  Have you any ideas, and what type of doctor (specialty) would be my best choice to search for answers ?????

[HFHS-MD-dm]

Dear Mr. Mammen:
I find your question very interesting and concerning.  I understand that you had your left lung removed in Jan of 1998 because of a lung cancer.  A  CT scan in April did not show any liver masses but a scan in July of 1998 now shows a new 1 cm mass.  This lesion has been further evaluated by and MRI or sonogram but you do not state what information the additional tests show.  
First and foremost, we liver specialists always like to see the CT scans for ourselves and in your case the MRI and sonogram as well.  Not all liver masses are the same.  Sometimes by looking at the lesion, we can get some idea of what it is.  The fact that you have had a CT scan, an MRI and a sonogram means there is a lot of information potentially available (which I do not have).  In addition, the location of the lesion can often tell us what some of our options are.  However, if you did not have a lesion In April and you do in July, this is concerning because lung cancer can metastasize to the liver.  Moreover, your blood tests would not necessarily be expected to be abnormal.  
Finally, I am concerned about your question about with what sort of doctor should you consult.  It sounds as if some physician is ordering tests on you and I think you should start by asking that physician what the tests show and what needs to be done from here.  In general, oncologists (cancer specialists)  are excellent all around physicians for seeing the big picture.  I know you have an oncologist because you have received chemotherapy.  The oncologist can consult with radiologists, liver specialists (hepatologists) and liver surgeons as he or she feels is necessary.  
I hope this answer is helpful to you and I wish you good luck.  Your situation sounds complex.  If you do not feel you are getting answers to your questions you might want to get a second opinion.   I would certainly invite you to contact me either directly or through MEDHELP if you have any additional questions.  We are available at Henry Ford, at [phone].  I hope this answer is helpful to you.  
This response is being provided for general informational purposes only and should not be considered medical advice or consultation.  Always check with your personal physician when you have a question pertaining to your health.