Hello, Thank you for posting your query at DoctorSpring.com. I understand your concern.
Coming straight away to your problems - Small 6 mm plural-based nodule in right middle lobe. Nonspecific 3 mm groundglass nodule density in the right costophrenic angle. - what is my inference? - well accidentally detected nodules, small in size, but multiple. pleural based ( means located in periphery) No associated symptoms like pain, no other symptoms too.
These are the possibilities for those nodules :

Possibilities - infection ( OLD ONE, AND SETTLED LIKE HISTOPLASMOSIS), an area of absent blood supply( Infarcted area), occupational like asbestosis ( Or inhalational, but not occupation related) and lastly malignancy.

Correlation with patients esophagus and followup is suggested warranted.

What does groundglass mean ? Ground glass means a hazy appearance of a patch in lung. usually seen when there is a lack of air. ie air is replaced by blood, mucous,fluid,etc.
Problems - 6 mm is a bit big, multiple lesions doesn't make it easier too. So chances of a cancer has to be actively searched - either in lung / surroundings- like breast, esophagus, stomach etc.
Chances of it being a cancer increases with age, smoking history, and family history of cancers.

Correlation with espohagus is necessary to rule out a primary association of any tumours from esophagus.
Is this cancer?- Nothing diagnostic of cancer till now, but probability remains high. There are still possibilities of it being benign- causes i already listed.

I do recommend follow up with pulmonologist.
what can be done- A CAT guided biopsy / needle aspiration from the pleural based mass / bronchoscopic brushing from areas with ground glassing.
Alternatively a PET SCAN ( COSTLIER) can be done to find out if there are any cells in body requiring increased glucose uptake( USUALLY cancer / Active infections).

Hope this helps, would be glad to answer any follow-ups.
Regards
DR. JACOB GEORGE P
MD,FCCP