Correct!
3. Biopsy of a pulmonary nodule is required to make a diagnosis of lung cancer
This patient has several abnormalities on his CT scan done on February 28, 2013 including multiple lung masses, enlarged bilateral hilar and subcarinal lymphadenopathy and a small left pleural effusion. The largest mass in the left lower lobe measures 4.1 X 3.6 cm. Neither the masses nor the lymphadenopathy were apparent on the previous CT scan done in July, 2011. The mean doubling time of lung cancer is about 100 days although the range can be as broad as 30-500 days (2).
A cocci serology, either an antigen or antibody test, should be done in areas such as Arizona where coccidiomycosis is prevalent. However, negative cocci serologies do not exclude the disease. Our patient's cocci serology was negative.
Aspiration pneumonia can present as multiple lung nodules, especially when present in the lower lobes.
This patient’s doubling time for his largest lung mass was less than 30 days suggesting that this was not a lung cancer and might be from an inflammatory cause. PET scanning may be useful in the assessment of solitary pulmonary lung nodules. Several studies indicate that PET scanning appears to be valuable in deciding whether a nodule is benign or malignant, as well as in staging local regional and distant metastatic disease. In some centers, PET/CT scanners are available to allow more precise anatomic localization.
The short doubling time of the patient’s mass and his reluctance to undergo an invasive procedure prompted a PET scan (Figure 2).
Figure 2. Movie of the color-enhanced PET-CT scan (Upper Panels) and a black and white PET scan (Lower Panel) showing increased radiotracer uptake in the lung nodules and mediastinal lymph nodes.
A fine needle aspiration biopsy was performed but was nondiagnostic. Which of the following procedures is most likely to reveal a diagnosis?