Lung Adenocarcinoma Diagnosed in a Nodule After Initial Spontaneous Regression in Size

Widespread adoption of lung cancer screening programmes increases the detection of pulmonary nodules, both benign and malignant. Although guidelines exist to direct the management of nodules, they do not address the management of nodules that display atypical behaviour. Although rare, certain histotypes of cancer demonstrate spontaneous resolution without treatment. In some cases, this heralds a long-lasting remission, whereas in others the cancer may progress after initial regression. We describe partial spontaneous regression of a pulmonary nodule that subsequently progressed and was diagnosed as adenocarcinoma.