Colloid carcinoma of the lung: Current views

Colloid carcinomas of the lung are rare and unusual neoplasms. These tumors need special attention in order to be properly coded as primary pulmonary tumors as they closely resemble their extrathoracic counterparts in their morphologic and immunohistochemical characteristics. Even though, the latest version of the World Health Organization (WHO) has trivialized this entity into garden variety of adenocarcinomas, recently proposed guidelines on pulmonary adenocarcinomas have created some potential to bring back the controversy that appeared to have been settled a decade ago regarding these tumors. Thus, the current review will highlight not only the current concepts but also will bring the historical perspective in an effort to clarify some misconceptions regarding this rare entity.