Endobronchial growth patterns in peripheral adenocarcinoma of the lung

A 59-year-old man who underwent chest radiography to exclude pneumonia showed an irregular nodular shadow in the left lower lung. A subsequent CT scan revealed an irregularly shaped soft-tissue mass consisting of two components: a peripheral round mass with spiculated margins and a well-circumscribed branching tubular opacity extending medially. Pathologically, the nodular lesion was found to be a poorly differentiated adenocarcinoma, and was contiguous with the central tubular opacity that represented the endobronchial polypoid growth of tumor from the periphery towards the hilum. The bronchial wall was found to be uninvolved by tumor. The centripetal pattern of endobronchial growth of a peripheral adenocarcinoma has not, to the authors' knowledge been described previously.