Touch print cytology shows higher sensitivity than pleural lavage cytology for pleural micro-metastasis in lung cancer.

Many authors have used pleural lavage cytology for confirming pleural micro-metastasis in lung cancer, but the results showed relatively low sensitivity having positive range of 4-14%. So, if we have a method with higher sensitivity than lavage cytology, the significance of pleural micro-metastasis will be elucidated clearly. To detect micro-metastasis, we underwent touch print cytology using glass slides and lavage cytology. Just after thoracotomy, touch print was carried with 2 pieces of glass slide from the visceral pleural surface of tumor mass. Then, two lavage cytology were collected at the times of pre-resection and post-resection (after distilled water irrigation) using each 1 liter of saline. The glass slides and lavages were examined for confirming micro-metastasis of cancer cells. From June 1998 to May 2004, 146 tumor masses of lung cancer have been subjected. Among them, 127 sets of cytology slides were reviewed completely in the last one month. Touch print cytology was found to be positive in 81.9% (104/127), while lavage cytology in 4.7% (6/127) of pre-resection and in 0.8% (1/127) of post-resection. To detect pleural micro-metastasis, touch print cytology using a glass slide can be considered as an easy and effective method having higher sensitivity than lavage cytology.