Diagnosis Solitary pulmonary nodule

a solitary pulmonary nodule (indicated purple arrow) on ct scan of chest.

diagnosis can made lung biopsy. small biopsies obtained core needle or bronchoscopy commonly used diagnosis of lung nodules. ct guided percutaneous transthoracic needle biopsies have proven helpful in diagnosis of spn. several features distinguish benign conditions possible lung cancer. first parameter size of lesion: smaller, less risk malignant cancer. benign causes tend have defined border, whereas lobulated lesions or irregular margin extending neighbouring tissue tend malignant.

growth of nodules helps determine status (malignant, infectious, or benign) in body based on time takes volume double. typical values less 20 days, less 100 days, or more 400 days infection based, malignant, , benign nodules respectively.

if there central cavity, thin wall points benign cause whereas thick wall associated malignancy (especially 4 mm or less versus 16 mm or more). in lung cancer, cavitation can represent central tumor necrosis (tissue death) or secondary abscess formation. if walls of airway visible (air bronchogram), bronchioloalveolar carcinoma possibility.

an spn contains calcifications. patterns of calcification reassuring, such popcorn-like appearance of hamartoma. spn density below 15 hounsfield units on computed tomography tends benign, whereas malignant tumors measure more 20 hounsfield units. fatty tissue inside hamartomas have negative value on hounsfield scale.

the growth velocity of lesion informative: fast or slow growing tumors malignant, in contrary inflammatory or congenital conditions. therefore important retrieve previous imaging studies see if lesion presented , how fast volume increasing. more difficult nodules smaller 1 centimeter. moreover, predictive value of stable lesion on period of 2 years has been found rather low , unreliable.