Diagnosis of anal HPV and warts (condylomas)
HPV is a quite common infection of anal canal (15% in heterosexual, 70% in women and homosexual, 90% in HIV positive heterosexual. HPV infection is usually asymptomatic and cannot be detected with direct vision. HPV infection may manifest as small cauliflower like lumps (warts). Anal warts are usually caused by low-risk HPV subtypes. High-risk HPV subtypes may manifest as flat HGAIN dysplasias which are diagnosed with high resolution anoscopy. They can progress into anal cancer.
The diagnostic procedures used for diagnosis of anal HPV infection are the following:
- Visual examination of perianal skin for warts of perianal skin. Application of acetic acid (common vinegar) is mandatory when somebody looks for anal HPV infection. Acetic acid clears the mucus and precipitates nuclear proteins giving the HPV lesions a pale or dark grey color, depending on the grade of dysplasia.
- Examination of the anal canal with a hollow tube called anoscope. Acetowhitening helps in the detection of minute intraanal warts. No deeper examination is needed for assessing the HPV infection.
- High resolution anoscopy for a detailed examination of perianal skin and anal canal under high magnification. Application of acetic acid (vinegar) and Lugol solution is needed. HRA looks for minute condylomas, subclinical lesions, low grade infection of anal canal and flat premalignant HGAIN lesions.
- HPV typing– Hybrid capture or PCR are used for identification of the HPV subtype infecting anus. HPV subtypes are classified as high risk (HR-HPV) or low risk (LR-HPV).
- Anal cytology (pap smear) is performed for screening and diagnosis of precancerous dysplasias. Pap smear should be performed in people belonging to the high-risk group. If cytology reveals atypical cells, high resolution anoscopy under magnification should follow. High resolution anoscopy has a considerably higher diagnostic yield for diagnosis of preclinical precancerous dysplasias.
- The visual diagnosis of HPV infection or the grade of dysplasia (benign LGAIN or premalignant HGAIN) can be confirmed with the pathologic examination of resected specimens. Koilocytes are cells with hollow nuclei, which occur as a result of HPV infection.
Anal warts (condylomas) are the most common manifestation of anal HPV-infection. They are found usually in the anal canal, perianal skin and genital organs, rarely coccyx. Warts are small flat or cauliflower-like growths as the head of a pin or a pea, knuckles or horny with pointed edges. They can get a large size if neglected. Usually, they do not cause pain or discomfort and patients may be unaware that they are present. In some cases, they cause bleeding, itching and discharge.
Another manifestation of the HPV infection in the anus (especially some aggressive sub-types) is the precancerous dysplasia of the skin and the anal canal. Dysplasia does not cause any symptoms and cannot be detected by simple visual examination. It is recognized only by High Resolution Anoscopy.
Cancer of the anus is an uncommon malignancy that is associated closely with HPV infection of the anal canal. Anal cancer signs and symptoms are bleeding, pain or fullness changes in bowel movements, itching or a mass in anus. It is easily detected with visual examination or anoscopy. Its extent can be assessed with endoanal ultrasound or NMR. A biopsy is needed for confirmation of diagnosis.
PROCTOLOGY CLINIC- ATHENS GREECE