Effusion cytology of esophageal carcinoma.

Background: Effusions in patients with esophageal carcinoma have only been reported rarely, and the cytologic findings in these specimens have not been well described.

Methods: The authors reviewed 70 effusion specimens from 45 patients with known esophageal carcinoma, 37 of whom underwent resection.

Results: Seventeen specimens were from 10 patients with squamous cell carcinoma; only 1 specimen contained malignant cells. Fifty-three specimens were from 35 patients with adenocarcinoma. Twenty-one specimens from 10 patients with adenocarcinoma contained malignant cells; these included 17 pleural, 2 pericardial, and 2 peritoneal fluids. Lymph node involvement at the time of resection was a significant risk factor for the development of a malignant effusion. The cytologic features were similar to those of other adenocarcinomas, but >50% of the specimens were hypocellular and neoplastic cells were rare. Three of 48 negative specimens contained markedly atypical mesothelial cells that were misinterpreted as possibly malignant; in each case the findings resolved over time. These cells were smaller and the chromatin more smudgy than in the neoplastic cells. Patients with positive effusions were significantly more likely to die of disease than those with a negative effusion, and the average time to death was shorter (5.3 months vs. 17 months).

Conclusions: Malignant effusions are more common in patients with esophageal adenocarcinoma than those with squamous cell carcinoma. Markedly atypical mesothelial cells are a diagnostic pitfall in patients who undergo resection.