tb related to cancer

My mother was diagnosed with cancer defined as a metastic of unknown origin.  THe doctors have gone around and around with the primary origin.  They have said, breast, thyroid and lung but nothing set.  She has a history of thyroid cancer (papillary) diagnosed and treated about 20 years ago with removal of just the tumor.  The doctors are now saying that they'll treat it as if it were lung cancer.  The secondary sites are in the left node of her neck and over the sternum area.  She has been exposed to TB many many years ago, but never  received any treatment.  My question is, should this be something the doctors should look at.  AT present she has had 3 rounds of Chemo, being Tamoxifen, and carboplatin.  Is there something else we should do or look in to?

[National Jewish]

Because your mother's immune system is compromised by the chemotherapy, TB is a concern. She should be evaluated for TB, co-existent with the metastatic cancer. The evaluation should include a tuberculin test, a chest X-ray looking specifically for TB and, if sputum can be obtained, sputum exam (smear and culture) for TB.

[aali]

A related discussion, lung cancer was started.