Fig. 9.6 Typical appearance of benign tubal metaplastic epithelium of the endocervical canal. (A) Isolated ciliated columnar cells show nuclei that
may be higher in the cytoplasmic column than is seen in non-metaplastic endocervical cells. Note the terminal bar into which the cilia are attached (arrow).
(B) A pseudostratified strip of metaplastic epithelial cells. Nuclei are present at every level of the cell as opposed to only in the basal portion. This appearance
has a significant architectural overlap with strips characteristically seen in endocervical AIS and can create a major differential diagnostic issue. Tubal metaplasia
can also present as larger hyperchromatic crowded groupings as shown in (C). Cilia may be difficult to see or entirely absent in some cases (liquid-based
preparation, Papanicolaou x HP).
Fig. 9.7 Tubal metaplasia can present as (A) small or (B) large hyperchromatic crowded groups, especially when sampling devices obtain cells from high
in the endocervical canal. (A) Examination of the group shows a crowded, but uniform, architectural honeycombed pattern. Nuclei are relatively uniform and
show finely granular, homogeneous euchromatin. (B) In this low magnification example, the cells around the margins show clearly identifiable, even columnar
appearance (liquid-based preparation, Papanicolaou x (A) HP, (B) LP).