Papanicolaou smear sensitivity for the detection of adenocarcinoma of the cervix: a study of 49 cases.

BACKGROUND

Papanicolaou smear sensitivity for cervical adenocarcinoma (CVCA) is not well established. Also uncertain are the relative contributions to falsely negative diagnoses of sampling, screening, and interpretive errors.

METHODS

Papanicolaou smears were identified from all patients at our institutions with biopsy-proven cervical adenocarcinoma from 1988-1998. All available negative and unsatisfactory smears were reviewed.

RESULTS

Of 49 patients with CVCA, 66 smears initially diagnosed as negative and 4 smears initially diagnosed as unsatisfactory from 30 patients were identified. Thirty-two negative smears and 4 unsatisfactory smears from 19 patients were available for review. The retrospective diagnoses in the cases initially called negative were: unsatisfactory in 2, negative in 15, and atypical glandular cells consistent with either adenocarcinoma in situ (AIS) or CVCA in 15. Three of four smears initially called unsatisfactory had neoplastic glandular cells identified retrospectively. The 18 falsely negative or falsely unsatisfactory smears were from 13 patients obtained up to 5 years before biopsy diagnosis. These smears contained neoplastic cells likely to have been mistaken for lower segment endometrial cells (LUS) or endocervical cells with tubal metaplasia (TM) in 11, reactive endocervical cells in 6, and both in 1. In 16 of the 18 smears, the abnormal cells were abundant, although preservation was suboptimal in 6.

CONCLUSIONS

Sensitivity of a single Papanicolaou smear for CVCA was between 45% and 76% depending on the classification of negative slides that were not available for review, comparable to previously reported sensitivity for AIS. The diagnostic false-negative or false-unsatisfactory rate in reviewed smears was 50% (18 of 36). Diminished sensitivity is due to the under recognition of glandular neoplasia resembling LUS, TM, or reactive endocervical cells. Cancer (Cancer Cytopathol)