Pelvic lymph node metastases in prostatic carcinoma. The value of touch imprint cytology.

Touch imprint cytology is a simple, rapid, reliable, and highly sensitive procedure when used for detecting lymph node metastases in men with clinically localized prostatic adenocarcinoma who are undergoing staging pelvic lymphadenectomy. Thirty-five men admitted for this procedure had frozen sections performed on the lymph nodes removed at surgery. Of these 35 patients, 19 had touch imprints made of their lymph nodes. In five patients classified as having Stage D disease, positive frozen section correlated with permanent section. In two of these cases, touch imprint cytology was performed and was positive for malignant cells. In seven patients classified as having Stage D disease, frozen sections were negative. Permanent sections were positive for metastatic tumor in five of these patients. In four of these cases, touch imprint cytology was performed. In two cases, cytology and permanent sections were positive and, in two cases, cytology alone was positive. Factors that contributed to the false negative rate for frozen section were: the presence of micrometastases, fatty lymph nodes that were difficult to process, and sampling errors on the part of the pathologist. Touch imprint cytology overcame the deficits of frozen section and proved useful in detecting metastatic disease in lymph nodes.