Peroperative detection of patients with rectal cancer at high risk of local recurrence.

Identification at the time of surgery of patients with rectal carcinoma at high risk of local recurrence may allow a more rational decision to be made regarding the operative procedure to be performed. We have examined tumour bed biopsies and lymph nodes peroperatively using imprint cytology in 20 consecutive patients undergoing radical surgery for rectal carcinoma. The results were checked by subsequent paraffin section histology. We were unable to find lymph nodes in 6 cases (30%) peroperatively. Cytological and histological reporting of the tumour bed biopsies and lymph nodes concurred in 91% and 88% of specimens respectively. Peroperative cytology can differentiate between malignant and benign fixation of rectal tumours, can differentiate between hyperplastic and malignant lymph nodes and may be of value in identifying patients with rectal cancer at high risk of local recurrence.