Differential Diagnosis for a 38-year-old Male with a Sensitive Anus Bump on the Anal Sphincter

• Single most likely diagnosis:
  • Hemorrhoid: This is the most common cause of a painful bump on the anal sphincter. Hemorrhoids can be internal or external, and when they become thrombosed, they can cause significant pain and a palpable lump.
• Other Likely diagnoses:
  • Anal fissure: A tear in the lining of the anus can cause pain and a lump, especially if it becomes infected.
  • Anal abscess: A collection of pus in the tissues around the anus can cause pain, swelling, and a palpable lump.
  • Perianal hematoma: A collection of blood in the tissues around the anus can cause pain and a lump.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
  • Anal cancer: Although rare, anal cancer can present with a lump or mass in the anal region and is critical to diagnose early.
  • Rectal cancer: Similar to anal cancer, rectal cancer can present with a mass or lump and requires early diagnosis for effective treatment.
  • Infectious causes (e.g., herpes simplex, syphilis): Certain infectious diseases can cause painful lesions or bumps in the anal region and require prompt diagnosis and treatment to prevent complications.
• Rare diagnoses:
  • Condyloma acuminatum (genital warts): Caused by human papillomavirus (HPV), these can appear as bumps or growths in the anal region.
  • Anal melanoma: A rare type of skin cancer that can occur in the anal region, presenting as a pigmented lesion or lump.
  • Dermatological conditions (e.g., hidradenitis suppurativa, psoriasis): Certain skin conditions can cause bumps, lumps, or lesions in the anal region, though they are less common causes of a sensitive anus bump on the anal sphincter.