Hi, Based on the information provided, it seems that the PET City scan has detected a well-defined lesion in the upper lobe of her left lung that is mildly FDG avid, which suggests that the cells in the lesion are taking up glucose (a type of sugar) at a slightly higher rate than normal cells. The PET scan report also suggests that the possibility of carcinoid should be considered and that further evaluation through HPE (histopathological examination) correlation is advised. Carcinoid tumors are rare neuroendocrine tumors that can occur in various parts of the body, including the lungs. However, it s important to note that other conditions can also cause a well-defined lesion in the lung, such as infection or inflammation. The next step in your wife s evaluation will depend on several factors, including her medical history, symptoms, and physical exam findings. However, in general, the most common next step after a PET scan that suggests a possibility of cancer is to perform a biopsy of the lesion, either through a needle biopsy or a surgical procedure. This will allow the pathologist to examine the cells under a microscope and determine if they are cancerous, and if so, what type of cancer. I would strongly recommend that you follow up with your wife s doctor as soon as possible to discuss the next steps in her evaluation and management. It s important to remember that early detection and treatment of cancer can significantly improve outcomes, so it s essential to act promptly and follow through with all recommended tests and procedures. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Priyanka, General & Family Physician