For cytological examination of the esophagus, a small piece of gauze is rubbed past a suspected lesion by means of an esophageal dilator introduced over a rubber-tipped guide wire. Smears made from the material thus obtained contain large numbers of well-preserved cells. This facilitates accurate differentiation of benign from malignant lesions, since the probability of finding tumor cells in a case of cancer depends on the total number of cells sampled and correct identification requires cells in a well-preserved state. Except where esophageal varices are suspected, this method appears to be safe. No complications were encountered, and diagnostic accuracy was high.
Hershenson LM, Lerch V, Hershenson MA. ESOPHAGEAL CYTOLOGY BY A GAUZE-SPONGE SMEAR TECHNIQUE. JAMA. 1958;168(14):1871-1875. doi:10.1001/jama.1958.03000140033009