Purpose of review: We review the categorization and management of solitary pulmonary nodules.
Recent findings: The National Comprehensive Cancer Network guidelines were updated in 2018 and the revised Fleischner Society guidelines were published in 2017. The revised Fleischner Society guidelines published in 2017 have less frequent follow-up recommendations for incidentally detected pulmonary nodules with longer intervals between subsequent CT scans. The updated 2018 version of National Comprehensive Cancer Network lung cancer screening guidelines provide recommendations for screen-detected nodules based on a patient's risk of cancer. New molecular assays may be of use in patients with a pretest probability of malignancy less than 50%. When these tests indicate low risk, a strategy of follow-up CT imaging may be feasible, avoiding unnecessary invasive testing. However, further clinical utility studies are needed in this area.
Summary: Management options for pulmonary nodules include watchful waiting with follow-up CT imaging, PET imaging, or further invasive testing based on probability of malignancy. With a low estimated risk of malignancy in an incidentally detected solitary pulmonary nodule, longer intervals between follow-up CT scans are recommended for patients. For patients at high risk for malignancy or those with nodules of at least 8 mm, either incidentally, screen detected, or symptom driven, a diagnostic biopsy is necessary to establish the cause of a solitary pulmonary nodule.