Pleural cytologies in lung cancer without pleural effusions

Malignant pleural effusions significantly increase the stage of lung cancer with attendant worsening of prognosis. There is a paucity of literature evaluating malignant pleural lavage cytology in patients without pleural effusions. We propose to determine the incidence of malignant pleural cytologies in patients without pleural effusions who undergo curative resection for lung cancer and to identify any predictive risk factors for positive cytology.

Seventy-eight patients underwent curative resection for lung cancer. Lavage was performed before lung manipulation and after resection and cytologically evaluated.

Twelve pneumonectomies, 64 lobectomies, and 2 wedge resections were performed on 40 men and 38 women with an average age of 65.7 years. Fourteen percent had positive lavage cytology before lung resection with an 11% (6 of 53) incidence in stage I. A significant correlation to adenocarcinoma compared with squamous cell was found (p = 0.03) but not to stage, T or N status, grade, pleural invasion, or preoperative transthoracic needle biopsy.

The incidence of positive pleural cytology in otherwise stage I patients is disconcertingly high. Positive cytology may be a prognosticator of a more aggressive tumor biology.