Cytology and image cytometry after colonic lavage: a complementary diagnostic tool in patients with ulcerative...

Patients with extensive, long-standing ulcerative colitis have increased risk of colorectal cancer.

To improve the detection of high-risk patients, using a combination of colonic cytology, histology, and DNA image cytometry after segmental colonic lavage.

A series of 16 patients (8 high-risk patients) with ulcerative colitis were investigated.

After segmental lavage step, biopsies were obtained. Gradient centrifugation of the colonic fluid was performed for isolation and purification of epithelial cells. The smears and biopsy specimens obtained were stained for routine interpretation and for DNA image cytometry.

Segmental lavage could be performed in all patients. Specimens from two high-risk patients showed low grade dysplasia and atypia by means of histology and cytology, respectively. In one patient, without increased colorectal cancer risk, atypia was detected. Three patients in the high-risk group, two of those diagnosed as positive for dysplasia and atypia, showed aneuploidy histologically and cytologically. DNA aneuploidy, in cytological material, was found exclusively in three low-risk patients, one of those had atypia cytologically.

Isolation and purification of epithelial cells after segmental colonic lavage using density gradient centrifugation can be performed as part of routine endoscopy. It provides information about atypical cells and DNA aneuploidy as additional markers of malignant transformation. The combination of cytologic examination and DNA image cytometry might improve the detection of high-risk ulcerative colitis patients.