I have a 4x3mm sub plural nodule lower right lobe w/family history of lung and colon cancer. should i get further testing?

What were you told?: These little nodules are extremely common especially in areas where histoplasmosis is endemic, like my home in Kansas. If you look hard enough, probably a majority of folks have them. Unless your radiologist recommends an attempt at a biopsy, I'd forget about it or as maximum monitor it by imaging. There's really no test except biospy; and it's too small to hit easily with a needle.