Endoscopic ultrasound-guided fine needle aspiration is highly accurate for the diagnosis of perirectal recurrence of colorectal cancer.

Background: Endoscopic ultrasound-guided fine needle aspiration is highly accurate for the diagnosis of malignancies surrounding the gastrointestinal tract. There is a lack of information on the usefulness of this technique in the diagnosis of colorectal cancer recurrence.
Objective: The purpose of this work was to investigate the performance characteristics of endoscopic ultrasound-guided fine needle aspiration for the cytologic diagnosis of perirectal recurrence of colorectal cancer.
Design: This was a retrospective study on the clinical and radiologic suspicion of perirectal recurrence of colorectal cancer.
Settings: The study was conducted at 4 tertiary hospitals.
Patients: Consecutive patients with suspicion of perirectal recurrence of colorectal cancer undergoing endoscopic ultrasound-guided fine needle aspiration between 2000 and 2013 were included in this study.
Interventions: The study intervention was endoscopic ultrasound-guided fine needle aspiration.
Main Outcome Measures: Endoscopic ultrasound-guided fine needle aspiration performance characteristics and outcome (malignant or benign) were analyzed. The gold standard was cytologic results if malignancy or follow-up if benignity.
Results: A total of 58 patients were included (32 men; mean age, 64.2 ± 10.0 years [range, 44-88 years]). The location of the initial neoplasm was the rectum for 42 patients and the colon for 16 patients. Endoscopic ultrasound findings included a mass in the anastomosis (n = 8), perirectal fat (n = 23), lymph nodes (n = 20), or asymmetric thickness of the rectal wall (n = 6). Cytology showed malignancy in 38 patients (67%), benign features in 17 (30%), and was not evaluable in 2. Mean follow-up to confirm a benign outcome was 51.3 ± 30.3 months (range, 5.2-180.0 months). Final outcome was recurrence in 40 patients (69%) and benignity in 18 patients (31%). Performance characteristics of endoscopic ultrasound-guided fine needle aspiration were sensitivity (97%), specificity (100%), positive predictive value (100%), negative predictive value (94%), and accuracy (98%). In the intention to diagnose analysis, the corresponding values were 95%, 100%, 100%, 90%, and 96%.
Limitations: This was a retrospective series with a limited number of patients.
Conclusions: Endoscopic ultrasound-guided fine needle aspiration is a highly accurate tool for the cytologic diagnosis of perirectal recurrence in patients with previous colorectal cancer.