IV. Premalignant and Malignant Neoplasms
After completing this tutorial the student will be
- classify the premalignant conditions and malignant
tumors of the vagina
- describe epidemiologic features
- describe clinical appearance
- describe/recognize histologic features and grade lesions
- predict clinical behaviour
- Vaginal Intraepithelial Neoplasia VAIN ("Dysplasia")
VAIN is much less common than cervical or vulvar dysplasia. It may occur
as an isolated lesion but more commonly (75% of cases) a pre- or co-existing
squamous carcinoma of cervix or vulva is present or VAIN may develop later.
This may be due to a field effect involving the squamous epithelium of the
lower genital tract (which arises from a common cloacogenic origin) that is
affected by the same carcinogenic agent. Risk factors include dysplasia elsewhere
in genital tract, HPV infection and in utero exposure to DES.
Question. What is the clinical implication of this "field effect"?
The lesion is asymptomatic and often no grossly identifiable lesion can be
seen. Diagnosis is usually considered because of an abnormal Pap smear result
in a woman with no demonstrable cervical abnormality or who has had hysterectomy.
This is confirmed ultimately by colposcopy and biopsy.
As with other intraepithelial neoplasia, there are architectural abnormalities
in the form of loss of epithelial cell maturation towards the surface (loss
of polarity). Cytologic abnormalities occur with dysplastic cells showing
nuclear hyperchromasia and pleomorphism, undifferentiated cells resembling
the basal cells scattered within the epithelium, and cellular crowding. Mitotic
figures, some abnormal, are increased and may be present above the basal layer.
The severity of VAIN is graded according the proportion, in thirds, of the
total thickness of the epithelium replaced by dysplastic cells.
- VAIN 1: Mild
- VAIN 2: Moderate
- VAIN 3: Severe. Carcinoma in situ may be used when dysplastic cells involve
the full thickness of the epithelium and there is no invasion of the underlying
The lesion may regress spontaneously, may recur after treatment, or progress
to invasive squamous cell carcinoma if left untreated.
- Invasive squamous cell carcinoma
Invasive squamous cell carcinoma of the vagina is much, much less common
than its counterpart in the cervix or vulva. Extension or metastasis from
a cervical or vulvar primary must be excluded. A tumor should not be considered
to be primary vaginal carcinoma unless the cervix is uninvolved or minimally
involved by a tumor obviously arising in the vagina. By convention, any cancer
involving both cervix and vagina that is histologically compatible with a
primary in either organ is classified as cervical. Likewise, tumors involving
the vulva and vagina are classified as vulvar cancers.
Most patients are postmenopausal (peaks at 60 to 70 years).
Most tumors arise in the proximal (upper) third of the vagina. They may occur
as an exophytic mass or an endophytic ulcer.
The tumors show varying degrees of histologic differentiation ranging from
well differentiated through to poorly differentiated.
This depends on the stage of the disease. Direct extension into soft tissue
of the pelvis or to the mucosa of the bladder or rectum occurs early because
the wall of the vagina is thin and is separated from these structures by scant
- Botryoid (Embyonal) rhabdomyosarcoma (sarcoma botryoides)
Botryoid rhabdomyosarcoma is a rare malignant tumor of mesenchymal origin
that arises in the lamina propria of the vagina. Over 90% of cases occur in
girls under 5 years of age.
The patient presents with vaginal bleeding or smooth, glistening, "grape-like",
polypoid masses (hence the name "botryoid"; "grape-like")
that fill the vagina and often protrude through the introitus.
Smooth, glistening, "grape-like" masses protrude through the vagina
and fill the introitus.
Microscopically, the tumor, covered by intact vaginal epithelium, comprises
spindled or round cells (rhabdomyoblasts) loosely dispersed in a myxoid stroma.
Immediately subjacent to the surface epithelium is a dense layer of tumor
cells called the cambium layer. Focal evidence of skeletal muscle differentiation,
in the form of cross-striations, may be present.
Dark, small round cells loosely dispersed in myxoid stroma.
The tumor invades extensively and metastasizes widely to regional lymph nodes
and hematogenously to distant sites. Direct spread occurs into the bladder,
rectum, and soft tissues of the pelvis. Historically, the prognosis after
radical surgery has been very poor. However, it has improved with the introduction
of adjuvant chemotherapy.