Incidence Anal canal cancer is a relatively rare tumor, representing approximately 1. It is approximately 20 to 30 times rarer than colon cancer, but its annual incidence is increasing, reaching up to cases, with a female predominance 2.
Cancerul de canal anal - aspecte legate de diagnostic și tratament
There is an important geographic variation regarding its incidence, as well as histopathological type. The mainstay of the treatment is represented by chemo-radiotherapy, radical surgery being reserved to residual tumor or recurrences. Table 1; AJCC staging for anal cancer 2. Histopathology Depending on the lining epithelium, anal canal is divided into three regions: colorectal zone: located proximally and containg columnar epithelium; transitional zone: spread over a distance that varies between 0 and 12 mm that contains a pseudostratified type of epithelium resembling the urothelial one.
Diagnostic Pathology GI Endoscopic Correlations
A transformation zone is unanimously accepted in uterine cancer. This region of metaplasia squamous papilloma colonoscopy extremely susceptible to HPV action 4 ; squamous zone: contains a non-keratinized epithelium, without hair follicles. Leiomyosarcomas, lymphomas and small cell carcinomas similar in terms of evolution and prognosis to lung small cell carcinomasundifferentiated carcinoma or anal GIST - only 17 cases described in literature up to 7 - have also been reported.
Concerning anal margin neoplasia, these are represented by: Bowen disease in situ squamous-cell carcinoma ; invasive squamous-cell carcinoma; Paget disease; basal cell carcinoma: an extremely rare cancerul col uterin, approximately 20 cases having been reported in 20 years 28that is of good prognostic.
The treatment consists in ample local resection or rectal amputation in case of sphincter invasion. TNM staging Anal cancer staging is based on tumor dimension, lymph node status and presence or absence of distance metastases.
The risk of lymph node metastases is correlated with tumor size, invasion and grading. Risk factors Benign perianal pathology - perianal fissures and fistulas determine a chronic local inflammation that can lead to genetic alterations and have squamous papilloma colonoscopy incriminated as being etiologic factors.
However, recent studies did not show a significant correlation between this pathology and the development of anal carcinoma 8. Sexual activity - according to a study lead by Daling, patients with anal cancer had genital papillomatosis, type II HSV and Chlamydia trachomatis infections in their medical history.
In the case of male patients, homosexuality, bisexuality, history of genital papilomatosis or gonorrhea have been associated to a higher risk of anal cancer 9. Another study, published inadds to the risk squamous papilloma colonoscopy, squamous papilloma colonoscopy females: history of gonorrhea, uterine cervix dysplasia, more than 10 sexual partners, anal sexual intercourse; for male patients: syphilis is another risk factor HPV infection - it is the widest spread sexually transmitted infection in Europe Anal HPV infection can be clinically inapparent or it may manifest as condyloma.
Of all HPV subtypes, subtype 16 is the most frequently incriminated as carcinogen.
Prevenirea cancerului prin intermediul unor programe de screening
Viral transmission is not influenced by the use of condoms as it is localized at the base of the penis and scrotum. Cigarette smoking - a study conducted in the early s highlighted a relative risk of 1. Carcinogenesis associated to cigarette smoking can be linked to an anti-androgenic effect of tobacco.
HIV squamous papilloma colonoscopy - some studies showed an increase in anal canal cancer in seropositive patients. The severity and length of HPV infection are inversely proportional correlated to CD4 lymphocyte number. Immunocompromised patients, either due to HIV infection or to post-transplantation status or chemotherapy, have an papiloma boca y garganta risk of HPV infection and progression to squamous cell carcinoma Anatomy Surgical anal canal spreads from ano-rectal ring 2 cm above the dentate line to the external anal orifice.
Anal cancer must be distinguished from anal margin neoplasia that originates from the skin that presents perianal hair. Some authors consider a 5 cm distance from the external anal orifice as the lateral limit The correct classification of perianal neoplasia into the two mentioned categories is extremely important as those of anal margin are of better prognosis.
Altogether, an erroneous classification could overestimate the role of radio-chemotherapy Pectinate line represents an extremely important landmark for the vascularization and lymph node drainage. Thus, above this line, venous squamous papilloma colonoscopy is to the portal circulation, by way of inferior mesenteric vein squamous papilloma colonoscopy below venous blood drains into systemic circulation through pudendal and hypogastric veins.
Above the pectinate line lymphatics drain into the inferior mesenteric, but also to hypogastric and obturatory lymph nodes, while below pectinate squamous papilloma colonoscopy to inguinal lymph nodes, but also to femoral ones Due to the resemblance to benign perianal pathology, the diagnosis is too often delayed.
Clinical examination consists in the inspection of perianal skin, anal margin, rectal examination and anoscopy and should indicate tumor squamous papilloma colonoscopy above or below the pectinate line or its pertaining to anal margin.
Bilateral inguinal region palpation is mandatory due to the lymphatic drainage to those lymphatic groups. Echo-endoscopy points our eventual loco-regional lymphadenopathies and gynecologic examination can indicate the coexistence of papiloma no utero uterine cervix lesion. The diagnostic of squamous squamous papilloma colonoscopy colonoscopy is based on histopathologic examination. Bioptic samples can be easily obtained with the patient in gynecological position; however, colonoscopy with exploration up to the cecum is obligatory to exclude eventual synchronous lesions.
As with other paraclinical investigations, a CT examination of the thorax, abdomen and pelvis or an MRI is recommended to point out possible secondary tumors. Untill the s, standard treatment consisted in abdominoperineal rectal amputation.