A totally Positron Emission Tomography (PET) negative lung cancer

Abstract

Lung carcinoma is the leading cause of cancer-related death worldwide. About 85% of cases are related to cigarette smoking. A 68 yo man referred to our office because of a mass of about 18 mm, non spiculated, in the upper right lobe found by a CT scan after a Thorax Radiography done during a routine check-up for a tyroid surgery (goiter). He was a heavy smoker (about 40 py, quit in 2013) but he hadn’t any other risk factor for lung cancer. He didn’t report weight loss, or other symptoms apart of his “usual” cough. A PET and a Fibrobronchoscopy (FBS) were performed and both turned out completely negative. A CT scan was repeated after 3 months and showed an increase in dimensions of the mass now circa 21 mm with the same characteristics. A percutaneous needle biopsy was performed and the diagnosis was adenocarcinoma of the lung with lepidic growth.. A bone scintigraphy turned out negative and a CT scan of the brain/abdomen didn’t show methastasis; the stage of the cancer was IA (T1bN0M0). We asked for a lung function test with carbon dioxide diffusion capacity. They were permissive for a right upper lobectomy, so that the patient underwent thoracic surgery. Pulmonary adenocarcinoma (PA) is the most common histologic type of primary lung cancer. Among the subtypes of PA, lepidic-predominant adenocarcinoma has the most favorable prognosis. 18 FDG PET has a sensitivity of 96%, specificity of 78%, and accuracy of 92%. SPNs are assessed by either visual method or SUV measurement; both are comparable and have similar accuracy. Lung cancers with negative PET findings are usually early-stage diseases and those that are PET negative should be managed to monitor for signs of growth.