Ann Thorac Surg 2002;73:1556-1557
© 2002 The Society of Thoracic Surgeons
Ronald B. Ponn, MDa
a General Thoracic Surgeons of Connecticut, 330 Orchard Street, Suite 300, New Haven, CT 06511 USA
The authors describe a novel technique for assessing the visceral pleura during operations for lung cancerintraoperative touch cytology (ITC). Overall, ITC was positive in 17% of cases versus 7% for pleural lavage cytology (PLC). It is noteworthy that ITC was positive in a significant number of patients without pleural transgression detected by standard histology. There are several potential ramifications of these findings. The first question is whether this technique should supercede standard histology in classifying the T factor for staging lung cancer. Unless and until there is considerable further experience, the answer must be negative. If a surgeon is concerned that invasion has been missed by the pathologist, he or she should request further cuts. What we see grossly as visceral pleural puckering is not always pleural involvement, but may be a desmoplastic reaction to the underlying neoplasm. Second, the relationship of ITC and PLC cytology is obvious. Both techniques are based on the detection of malignant cells that have exfoliated from the primary tumor into the pleural space (lavage) or can be assumed to have a high potential to do so (touch). This preliminary study suggests that the touch prep may be more sensitive. Although PLC was described over 60 years ago, the literature on the subject is limited. Different techniques have been used with respect to the amount and type of fluid and whether lavage is done presection, postresection, or both. In addition, the available experience varies in regard to associated risk factors for positive lavage, such as T and N factor, as well as stage in general. Very importantly, however, it is clear that patients who have a positive lavage, other factors being equal, have a significantly worse long-term survival than those with negative cytology. Nonetheless, this finding does not at present affect TNM staging nor is there a standard approach to postoperative adjuvant treatment in this setting.
It is clear from this study as well as those of PLC that during many operations for lung cancer, malignant cells are present in the pleural space and/or on the very surface of the lung. A personal practical approach to this fact is that I bathe the pleural space in distilled water after every resection in order to lyse cells. After resection, all operators change gloves and remove from the operative field all instruments or sponges that have contacted the tumor. This may be pure voodoo, but it is not harmful or difficult. One other practical use of this information may be in the area of parietal pleural involvement. There is debate as to whether extrapleural dissection is sufficient for tumors that involve the parietal pleura but can be easily peeled off the chest wall or if chest wall resection is needed. Although only a few such lesions appear in this series, one might consider using PTC in this setting as an intraoperative guide to proceed to chest wall resection (although not en bloc) or to help decide about adjuvant radiation. Again, all this is speculation, but ITC and PLC clearly deserve further study for diagnostic, prognostic, staging and therapuetic implications.
Diagnosis of visceral pleural invasion by lung cancer using intraoperative touch cytology
- Yushi Saito, Yosuke Yamakawa, Masanobu Kiriyama, Ichiro Fukai, Satoshi Kondo, Masahiro Kaji, Motoki Yano, Tomoki Yokoyama, and Yoshitaka Fujii
Ann. Thorac. Surg. 2002 73: 1552-1556.