The different histologic subtypes of lung adenocarcinoma (lepidic, papillary, micropapillary, acinar, and solid) often merge into one another imperceptibly and represent a continuum. In this image, the lepidic pattern seen in upper two-thirds transitions into acinar pattern in the lower third. The histologic components present in the resected specimen are assessed semi-quantitatively in 5% increments and the tumor is classified based on the predominant component present. Each of the other components are documented in the report due to prognostic implications. Micropapillary pattern, even when present in small amounts, has been associated with poor prognosis.