Clinicopathological characteristics of primary lung adenocarcinoma predominantly composed of goblet cells in surgically resected cases

Primary lung adenocarcinomas predominantly composed of goblet cells (APGC) are relatively rare, and the clinicopathological characteristics have remained unclear. The aim of this study was to clarify the clinicopathological characteristics of APGC. We selected adenocarcinoma with a goblet cell-type component of >= 90% from 2228 cases of surgically resected primary lung adenocarcinoma. The clinicopathological characteristics of APGC (46 cases) were analyzed. APGC showed a significantly higher rate of tumor location on the left side, in the lower lobe and pathological stage I, when compared with the other types of adenocarcinoma. Furthermore, APGC displayed a lower frequency of central fibrosis, plural invasion, pulmonary metastasis, lymphatic permeation, and vascular invasion. APGC showed local recurrence in two of 46 cases (4.3%) and no incidents of distant metastasis. When compared with non-mucinous bronchioloalveolar adenocarcinomas (non-mucinous BAC) without central fibrosis, APGC without central fibrosis, corresponding to mucinous BAC, showed a significantly higher rate of tumor location on the left side and in the lower lobe. In conclusion, APGC formed a distinct subset and should be considered separately from lung adenocarcinoma based on frequent involvement of the left and lower lung and lack of central fibrosis.