Transitional (urothelial) cell metaplasia of the fallopian tube mucosa: morphological assessment of three cases.

The origin of rarely encountered transitional cell carcinomas of the fallopian tubes has, to date, been ascribed to transitional cell metaplasia of the tubal serosa or subserosal Walthard rests. We report here three examples of transitional cell metaplasia of the mucosa of the fallopian tubes--in each instance an incidental finding--and propose this lesion as a hitherto unreported possible precursor for such tumors.