Anal Cancer: Clinical Presentation and Diagnostic Work‑Up

Typical Symptoms

Rectal bleeding is the most common presenting symptom, occurring in approximately 78 % of patients with anal cancer【1】.
Pruritus (itching) may be reported as a presenting symptom of anal cancer【1】.
Anal discharge is a recognized presenting symptom of anal cancer【1】.
Fecal incontinence can be a presenting feature of anal cancer【1】.
Perianal fistulae may be present in patients with anal cancer【1】.
A non‑healing ulcer in the anal region is a possible presenting sign of anal cancer【1】.

Digital anorectal examination (DRE) is an essential, low‑cost clinical tool for detecting anal lesions and should be performed in every suspected case【1】.
A complete medical history and a full clinical examination—including DRE—are required as the first step in evaluation【1】.
Histologic confirmation by biopsy is mandatory because several other malignancies (e.g., adenocarcinoma, melanoma, GIST, neuroendocrine tumor, lymphoma) can mimic squamous cell carcinoma of the anus【1】【3】.
In women, a vaginal examination is advised for low, anteriorly placed tumors to assess possible vaginal or vaginal‑septal involvement【4】.
Palpation of superficial inguinal lymph nodes—particularly those medial and close to the pubis—is recommended to detect nodal disease【4】.

High‑resolution pelvic MRI is the optimal imaging modality for evaluating local tumor extent and anatomic relationships【1】.
Contrast‑enhanced CT of the thorax, abdomen, and pelvis is indicated for distant staging of anal cancer【1】.
Whole‑body PET‑CT is recommended for comprehensive staging, especially to identify occult metastatic disease【1】.
HIV testing should be performed in any patient with unknown HIV status, given the strong association between HIV infection and anal cancer【1】.
Assessment of p16/HPV status is advised to inform prognosis and potential therapeutic decisions【1】.
Anoscopy or proctoscopy is part of the standard work‑up to directly visualize the lesion【1】.
A gynecological examination is recommended in female patients to evaluate possible extension to adjacent pelvic structures【1】.

Endo‑anal ultrasound may be used as an adjunctive tool for assessing depth of invasion【1】.
Ultrasound‑guided fine‑needle aspiration (FNA) of suspicious inguinal nodes can be performed to obtain cytologic confirmation of nodal involvement【1】.
Examination under anesthesia can facilitate thorough inspection and biopsy of lesions that are difficult to assess in the office setting【1】.

Colonoscopy is not required for the work‑up of anal squamous cell carcinoma because synchronous colonic lesions have not been reported in this disease【4】.
All suspicious anal lesions must be excised or biopsied; clinicians should not assume benign pathology based solely on appearance【4】.
Women with anal intra‑epithelial neoplasia should be screened for concurrent cervical, vulvar, and vaginal intra‑epithelial neoplasia owing to the shared HPV etiology【4】.
In cases of a large obstructing anal mass or tumor associated with fecal incontinence, a defunctioning stoma may be considered, recognizing that most initial colostomies are not later reversed【4】.