Anus

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The anus occasionally shows-up on the pathologists desk. It sometimes comes with the rectum and colon, as an abdominoperoneal resection (APR).

Anal neoplasia

Immunosuppressed individuals and homosexuals have a higher risk of anal intraepithelial neoplasia (AIN) and anal cancer.[1][2]

Anal intraepithelial neoplasia

  • Abbreviated AIN.

General

  • Precursor lesion of anal cancer.
  • Usually HPV associated.

Grading

AIN is graded much like cervical intraepithelial neoplasia:

  • High-grade anal intraepithelial neoplasia (HGAIN).
  • Low-grade anal intraepithelial neoplasia (LGAIN).

Anal cancer

Hidradenoma papilliferum

See Hidradenoma papilliferum.

Hemorrhoids

General

  • Benign.

Clinical features:[3]

  • Bright red blood per rectum (BRBPR).
  • Pain.
  • Itching.
  • Prolapse.

Gross

Features:[4]

  • Grey mucosa.
  • Pale or purple stroma.

Microscopic

Features:[4]

  • Polypoid lesion - epithelium on three sides:
    • Large dilated veins and thick-walled vessels +/- fibrin thrombi - key feature.
    • Edema.
    • Squamous epithelium +/- keratinization or columnar epithelium.

DDx:

Image:

See also

References

  1. Park IU, Palefsky JM (March 2010). "Evaluation and Management of Anal Intraepithelial Neoplasia in HIV-Negative and HIV-Positive Men Who Have Sex with Men". Curr Infect Dis Rep 12 (2): 126–133. doi:10.1007/s11908-010-0090-7. PMC 2860554. PMID 20461117. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860554/.
  2. Czoski-Murray C, Karnon J, Jones R, Smith K, Kinghorn G (November 2010). "Cost-effectiveness of screening high-risk HIV-positive men who have sex with men (MSM) and HIV-positive women for anal cancer". Health Technol Assess 14 (53): 1–131. doi:10.3310/hta14530. PMID 21083999.
  3. Cazemier, M.; Felt-Bersma, RJ.; Cuesta, MA.; Mulder, CJ. (Jan 2007). "Elastic band ligation of hemorrhoids: flexible gastroscope or rigid proctoscope?". World J Gastroenterol 13 (4): 585-7. PMID 17278225.
  4. Jump up to: 4.0 4.1 Iacobuzio-Donahue, Christine A.; Montgomery, Elizabeth A. (2005). Gastrointestinal and Liver Pathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Churchill Livingstone. pp. 401. ISBN 978-0443066573.