Lepidic AdenoCA VS Minimally-invasive AdenoCA

Comments:
Lepidic growth pattern is seen in both lepidic adenocarcinoma as well as in minimally-invasive adenocarcinoma (MIA) of lung. The diagnosis of lepidic adenocarcinoma is rendered if the tumor shows 1) vascular or pleural invasion; 2) tumor necrosis; 3) invasive component greater than 0.5 cm; or spread through air spaces. MIAs are less than or equal to 3 cm in size and have an invasive component less than or equal to 0.5 cm in greatest dimension.

The image shows lepidic adenocarcinoma; note the peripheral (subpleural) location of the tumor. Adenocarcinomas of the lung tend to be located more peripherally and are usually smaller in comparison to the pulmonary squamous cell carcinomas.