Impact of elastic staining on the staging of peripheral lung cancers

Accurate staging of lung cancer has a profound impact on patient management. For stage I nonsmall cell lung carcinomas (NSCLCs), the absence (stage IA) or presence (stage IB) of visceral pleural invasion represents a critical therapeutic branch point: patients with stage IB NSCLC benefit from adjuvant chemotherapy, whereas patients with stage IA NSCLC do not. Elastic staining has been advocated as a simple method for visualizing pleural invasion. The purpose of this study was to determine whether routine elastic staining of the resected peripheral NSCLCs alters tumor staging in a meaningful way. The study cases consisted of 100 consecutive peripheral NSCLCs resections that were pathologically staged as IA based on routine histologic assessment. Each case was stained with the Movats pentachrome elastic stain to aid identification of visceral pleural invasion. To assess current standards of surgical pathology practice, members of the American Association of Directors of Anatomic and Surgical Pathology were asked whether they never, sometimes, or always order elastic stains for peripheral NSCLCs that abut the pleura. Elastic staining resulted in a change of tumor stage from IA to IB in 19 (19%) cases. Of the 49 pathologists that responded to the survey, 25 (51%) never, 14 (29%) sometimes, and 10 (20%) always order an elastic stain for NSCLCs abutting the pleura. Elastic staining is currently not standard surgical pathology practice for the evaluation of peripheral NSCLCs, but it should be. Invasion of the pleura is an elusive finding that is best appreciated with an elastic stain. Our experience suggests that routine elastic tissue staining should be performed as a standard method of assessing pleural involvement for pleural-based nonsmall cell lung carcinomas.