Fig. 11.17 Melanoma of the vagina. (A) Histology (H&E x HP); (B) cytology. Large pleomorphic cells with binucleation and macronucleoli
Fig. 11.18 Vaginal metastasis of colorectal adenocarcinoma. (A) Histology (H&E x MP); (B) cytology. Malignant long columnar glandular cells with
enlarged and overlapping nuclei and dirty background (Papanicolaou xHP).
Fig. 11.19 Vaginal metastasis of papillary serous adenocarcinoma.
Large pleomorphic cells with enlarged nuclei and prominent nucleoli and
forming vague glandular configuration (Papanicolaou xHP).
The anal canal is composed of the colorectal zone, anal transfor-
mational zone (ATZ), and squamous zone.84 The colorectal zone
is covered with columnar cells of colorectal type; the ATZ con-
sists of variants of epithelial coverage with 4-9 cell layers. The
basal cells are rather small and have their nuclei arranged per-
pendicular to the basement membrane. The surface cells in ATZ
can be columnar, cuboidal, or polygonal. It resembles that of
the cervical transformational zone with metaplastic squamous
epithelium. ATZ often contains mucin-producing cells and
sometimes a few endocrine cells. The squamous zone includes
non-keratinized squamous mucosa and perianal keratinized
squamous skin with anal glands.84
Squamous cell carcinoma and Anal intraepithelial
Anal squamous cell carcinoma is a rare malignancy, account-
ing for only 4% of all cancers affecting the gastrointestinal tract.
However, it is the fourth most common reported malignancy