Primary vaginal carcinoma

Primary vaginal carcinoma, although being a rare overall, is still the 5^th commonest gynaecological malignancy. A primary vaginal carcinoma is defined as a neoplasm that arises solely from the vagina with no involvement of the external os superiorly or the vulva inferiorly, the importance of this definition lying in the fact that the most of malignancies involving the vagina are due to invasion from nearby tumours and the different clinical approaches in the treatment of cervical carcinoma and vulval carcinoma.

Epidemiology

It can account for 1-3% of all gynaecologic malignancies. The typical age at presentation is at around the 6^th to 7^th decades of life.

Pathology

The tumourLesions characteristically arises fromarise from the posterior wall of the upper third of the vagina. The common patterns of disease are:

• an ulcerating or fungating mass or 
• an annular constricting lesion

Histological subtypes

• squamous cell carcinoma of the vagina: by far the commonest accounts for ~80-85% of primary vaginal malignancies, presents in older individuals
• adenocarcinoma of the vagina: ~15% second commonest subtype, presents in younger individuals and arising from vaginal adenosis
  • clear cell carcinoma of the vagina: rare, previous diethylstilbestrol (DES) exposure
• primary vaginal melanoma
• vaginal sarcoma: rhabdomyosarcoma in paediatric population
  • botryoid rhabdomyosarcoma

Radiographic features

Pelvic MRI

Imaging features will somewhat depend on the histologcial type of malignancy. 

Reported general signal characteristics in general include ⁶:

• T1: isointense to muscle
• T2: high signal intensity compared with muscle

Reported signal charactersitics for squamous cell carcinoma include ¹:

• T1: low signal intensity
• T2: intermediate signal intensity

Staging 

See: vaginal cancer staging

Treatment and prognosis

Prognosis is significantly dependent on stage. Carcinoma in situ and very early stage invasive carcinoma is often treated with surgery. However, the standard therapeutic intervention for patients with carcinoma of the vagina is radiation therapy. Advanced stages are often treated with radiography and chemotherapy (e.g. Cisplatin)

Differential diagnosis

For large lesions consider invasion of the vagina by:

• cervical carcinoma
• rectal carcinoma
• uterine carcinoma

Malignant involvement of the vagina from metastatic spread is much more common, and except for isolated reports of metastases from extragenital cancers, the most common cause of metastatic disease is direct local invasion from the female urogenital tract. Therefore some authors state the diagnosis of primary vaginal carcinoma should be diagnosed only if other gynecologic malignancies have been excluded.

Other differential considerations include:

• vaginal lymphoma