An Invasive Lepidic Predominant Adenocarcinoma Extensively Involving the Lung with Areas of Sarcomatoid Carcinoma Containing Osteoclast-like Giant Cells.

Primary lung tumor tissue exhibiting numerous multinucleated osteoclast-like giant cells (OGCs) is an extremely rare histological type. In this study, we describe the case of an 82-year-old woman. Chest CT demonstrated an extensive crazy-paving appearance in both of the lung fields and a solid round mass in the right lower lobe. A pathological examination of the tumor revealed sarcomatoid carcinoma containing OGCs combined with diffused, invasive lepidic predominant adenocarcinoma. We herein present an extremely rare lung cancer, invasive lepidic predominant adenocarcinoma extensively involving the lung with areas of sarcomatoid carcinoma containing OGCs.