TUBAL METAPLASIA OF THE UTERINE CERVIX - A PREVALENCE STUDY IN PATIENTS WITH GYNECOLOGIC PATHOLOGICAL FINDINGS

Tubal metaplasia (TM) of endocervical epithelium may be confused with endocervical dysplasia or adenocarcinoma in histologic or cytologic specimens. However, the potential magnitude of this problem is unknown, because the prevalence of endocervical TM in routine surgical pathology material is undefined. To determine the prevalence, distribution, and associated features of endocervical TM, we retrospectively reviewed a consecutive series of cone biopsy specimens (n = 82) and hysterectomy specimens in which the entire cervix had been sectioned (n = 26), obtained over 28-months. Tubal metaplasia was defined as epithelium containing all three cell types (ciliated, secretory, and intercalary) found in the normal fallopian tube. The mean patient age was 41 years (range, 21-79). Endocervical TM was present in 33 of 108 patients (31%) and was evenly distributed among all age groups. Its prevalence was related to the number of sections examined (23% of cases with less-than-or-equal-to 12 blocks of the cervix; 52% of cases with > 12 blocks; p < 0.01) and was greater in hysterectomy than in cone specimens (62 vs. 21%, p < 0.001). Although most frequent in the upper endocervix and in deep portions of glands, TM involved the surface in 36%, the superficial parts of glands in 64%, and the lower endocervix in 30% of positive cases. There was no association with phase of the menstrual cycle, inflammatory changes, or low-grade cervical intraepithelial neoplasia (CIN), but TM was inversely related to high-grade CIN in glands, presumably due to replacement of metaplastic cells by neoplastic cells. In conclusion, TM is frequent in patients with lower genital tract pathologic findings and is often present in locations easily sampled by cytologic or biopsy techniques. Awareness of its presence may avoid overinterpretation of TM as endocervical neoplasia.