Novice colposcopists should routinely perform endocervical curettage (ECC) on all patients (except for pregnant women). ECCs are particularly recommended when colposcopy is unsatisfactory or no lesions were observed. Failure to do ECC can have serious consequences; invasive cancer may develop after outpatient evaluation and treatment if this step is overlooked. Unifocal dysplasia or neoplasia is found in the majority of cases. On occasion, however, patients have multifocal lesions in the upper endocervical canal that may not be visualized with the colposcope. ECCs are also helpful in identifying an early adenocarcinoma that may be difficult to distinguish from the normal endocervical anatomy with the colposcope.

Some investigators have suggested that cytobrush sampling of the endocervical canal may be substituted for an ECC, but this has not been uniformly accepted. The endocervical curette provides the greatest test specificity (limits false positives) and as such may be the best tool for diagnostic purposes during colposcopy. An aggressive cytobrush sampling of the canal is a more sensitive test (limits false negatives) and therefore represents the better screening tool for Papanicolaou smears (Shier, Ferris).