1. Department of Pulmonology, Kameda Medical Center, 929 Higashi-cho, Kamogawa 296-8602, Chiba Prefecture, Japan
2. Department of Anatomic Pathology, Kameda Medical Center, 929 Higashi-cho, Kamogawa 296-8602, Chiba Prefecture, Japan
3. Postgraduate Clinical Training Center, Kameda Medical Center, 929 Higashi-cho, Kamogawa 296-8602, Chiba Prefecture, Japan
4. Department of Medical Oncology, Kameda Medical Center, 929 Higashi-cho, Kamogawa 296-8602, Chiba Prefecture, Japan