Case Presentation - Fall, 2004

History: 37 year old, male

Specimen Type: FNA of groin mass.

Case provided by: Stan Lightfoot, MD of the Department of Veteran Affairs Medical Center, Oklahoma City, OK.

NOTE: The diagnosis and analysis for this case study were provided by an independent physician. All conclusions and opinions are those of the physician and not Hologic, Inc.

Cytologic diagnosis: Metastatic Squamous Cell Carcinoma.

Histologic diagnosis of previous anal lesion: Squamous cell carcinoma of the anus.

Patient follow-up: Patient received radiation therapy. At this time the patient is free of disease.

Despite the fact that anal cancer is a fairly rare form of malignancy, the number of new anal cancer cases each year is increasing. According to the American Cancer Society, 4,010 new cases of anal cancer will be diagnosed in the United States in 2004.

Anal cancer affects women more often than men. In women the cancer usually develops in the inner part of the anus (the anal canal), while anal tumors in men tend to develop on the external part of the anus. Anal cancer can pose a serious health condition and an estimated 580 people will die of this cancer in 2004.

Although the exact cause of anal cancer is unknown, certain individuals are at higher risk. Smokers, individuals with chronic conditions, such as fistulas, and individuals with human papilloma virus (HPV) infection are in high risk for developing anal cancer.

Various epidemiological studies have shown that sexually transmitted infection with human papillomavirus is a major factor in the development of anal cancer. More than 100 types of HPV have been identified. As with cervical cancer, HPV-16 is often associated with the development of squamous cell carcinoma of the anus.

Recent scientific investigations using anal cytology have incorporated the morphologic criteria of squamous cell lesions of the cervix. Squamous cell carcinomas produce a range of morphological types from well-differentiated keratinizing tumors to poorly differentiated non-keratinizing tumors. In keratinizing squamous cell carcinoma, the cells are often isolated and can form unusual shapes, resembling tadpole or spindles. The cytoplasm of the malignant cells is densely orangeophilic. The nuclei are dark, often pyknotic and they can vary in size and shape. Tumor diathesis is usually found in the background and is often used as a hallmark of invasion. Macronucleoli and coarse chromatin may be present but are usually seen in cases of non-keratinizing squamous cell carcinoma.

Treatment and Prognosis
In previous years surgery, involving abdominoperineal resection and permanent colostomy, was the treatment of choice for many institutions. This treatment provided a 5-year survival rate of approximately 70% but decreased the patient's quality of life. Currently the standard of care consists of external-beam radiation therapy and chemotherapy with fluorouracil and mitomycin. This chemoradiation therapy provides a similar 5-year survival rate with less patient morbidity.

  1. Cibas, E., Ducatman, B.: Cytology Diagnostic Principles and Clinical Correlates.1996: 28-30.
  2. Bibbo, M: Comprehensive Cytopathology. 1997: 437-438.
  3. Mendenhall W, Zlotecki R, Vauthet J, Copeland E. Squamous Cell Carcinoma of the Anal Margin. Oncology 1996; 10.
  4. American Cancer Society. Cancer Facts and Figures 2004. Atlanta, GA: American Cancer Society; 2004.
  5. Esiashvill N, Landry J, Matthews RH. Carcinoma of the anus: Strategies in management. The Oncologists 2002; 7: 188-199.
  6. Gervaz P, Allal A, Villiger P, Buhler L, Morel P. Squamous cell carcinoma of the anus: Another sexually transmitted disease. Swiss Med Wkly 2003; 133: 353-359.
  7. Ryan DP, Compton C, Mayer RJ. Carcinoma of the anal canal. N Engl J Med 2000; 342: 792-800.
  8. Friedlander MA, Stier E, Lin O. Anorectal cytology as a screening tool for anal squamous lesions cytologic, anoscopic, and histologicv correlation. Cancer2004 Feb 25;102(1):19-26.
  9. Darragh TM. Anal cytology for anal cancer screening: Is it time yet? Diagn Cytopathol 2004; 30:371-374.