An **Anal Canal - Medium Biopsy (1-3cm) Diagnostic Test** is a histopathological examination performed on tissue samples measuring between one and three centimeters excised from the anal canal. This diagnostic evaluation is typically ordered by a physician when a physical examination, anoscopy, or sigmoidoscopy reveals abnormal mucosal changes, suspicious lesions, polyps, or persistent ulcers.

A pathologist meticulously analyzes the biopsy specimen under a microscope to identify cellular abnormalities, determining whether the tissue is benign, inflammatory, precancerous, or malignant. This test provides critical data needed to differentiate conditions like anal intraepithelial neoplasia (AIN) from invasive carcinomas, guiding precise treatment planning.