Consult the medical resource doctors trust
UpToDate is one of the most respected evidence-based medical information resources in the world, used by over 400,000 doctors and thousands of patients to find answers to medical questions.
Related articles
As a subscriber you will have access to the full contents of this article
INTRODUCTION
Bronchioloalveolar carcinoma (BAC) is a subtype of adenocarcinoma of the lung that is distinguished by its peripheral location, well-differentiated cytology, growth along intact alveolar septa (the so-called "lepidic" growth pattern), and tendency for both aerogenous and lymphatic spread. In the World Health Organization (WHO) classification of lung tumors, BAC is considered a subset of adenocarcinoma [1].
BAC is divided into mucinous, nonmucinous, and mixed subtypes. This distinction is based upon histologic criteria, and is supported by immunohistochemical and molecular biology differences. Distinguishing mucinous from nonmucinous subtypes of BAC has significant therapeutic and prognostic implications [2].
The clinical presentation and treatment of pure BAC and mixed adenocarcinoma with a BAC component will be reviewed here. The presentation and treatment of other forms of NSCLC are discussed elsewhere. (See "Overview of the treatment of advanced non-small cell lung cancer" and "Overview of the initial evaluation, treatment and prognosis of lung cancer".)
EPIDEMIOLOGY AND RISK FACTORS
Incidence — Over the last several decades, the proportion of lung cancers classified as adenocarcinoma has steadily increased and now represents approximately one-half of all cases [3].
The incidence of the BAC subset is uncertain. In the United States, estimates of the incidence of BAC have varied from as high as 24 percent in a single institution series [3] to less than 5 percent in a large series based upon the Surveillance, Epidemiology and End Results (SEER) database [4]. These differences probably reflect variation in the application of pathologic criteria for the diagnosis of BAC. (See 'Histologic features' below.)
» To continue reading this article you need to login or subscribe.
![]() |
Please wait |