Thanks for your question on HCM.
I can understand your situation and problem.
In my opinion you should
consult oncologist (cancer specialist) and get done
1. PET scan
2. Blood work up for tumour markers.
To search for the primary site of malignancy.
He is having metastatic nodules in lung. This suggest that he is having primary somewhere else in the body.
Following are the malignancies, commonly metastasize to lung.
1. Liver
2. Intestine
3. Stomach
4.
Thyroid etc.
So ,he needs PET scan to identify the primary site.
Because PET scan will give hot spot at the site of malignancy due to high uptake of contrast.
So it will help in diagnosis of primary.
Treatment is based on primary organ only.
Mostly he will need
chemotherapy and radiotherapy and other supportive drugs.
So better to consult oncologist and discuss all these.