An update on tumors of the anal canal.
ABSTRACT The anal canal possesses complex anatomy and histology and gives rise to a variety of tumor types. Challenging issues remain with regard to both the pathologic diagnosis and the clinical management of these tumors.
To provide an updated overview of the histogenesis, clinical and pathologic characteristics, diagnostic terminology, and relevant clinical management of the various types of anal canal tumors.
Recent literature on clinical and pathologic characteristics of anal canal tumors.
Although most anal canal tumors are of squamous lineage, a complex variety of other tumors also occurs. Recognition of such diverse tumor entities will allow accurate pathologic diagnosis and most optimal clinical management.
- SourceAvailable from: Umesh Kapur[Show abstract] [Hide abstract]
ABSTRACT: Squamous cell carcinoma of the anus is a relatively uncommon GI malignancy. When it does occur, it metastasizes in only a small minority of patients. Spread of anal squamous cell carcinoma to the brain is exceedingly rare, and has been previously reported only three times in the medical literature. We report the case of a 67 year old male who was diagnosed on presentation with a poorly differentiated anal squamous cell carcinoma that already had a solitary metastasis to the liver. While the tumors were initially responsive to chemoradiotherapy, the patient's primary and liver lesions recurred. The patient then underwent synchronous abdominoperineal resection for the primary lesion and a liver lobectomy for the metastasis. Soon thereafter, the patient developed focal neurologic symptoms and was found to have an intracranial lesion that on biopsy demonstrated metastatic squamous cell carcinoma. This case highlights the fact that patients with a previous history of anal squamous cell carcinoma can occasionally develop cerebral metastasis. Furthermore, cerebral metastases from anal squamous cell carcinoma portend a dismal prognosis even in the face of aggressive medical and surgical therapy.10/2012; 2012:912178. DOI:10.1155/2012/912178
Article: Malignancies of the anal canal[Show abstract] [Hide abstract]
ABSTRACT: The carcinomas of the anal canal consist of truly rare clinical entities compared to the most common colorectal malignancies. Consequently, little have been reported on their natural history and course. The present study is aiming to describe the experience of our clinic with anal cancer and to clarify the incidence of the disease in the Hellenic population. A 5-year retrospective study was conducted. We searched all cases of patients, diagnosed with anal carcinoma in our medical center. Medical records and histological examination results were all thoroughly registered and evaluated. On the whole, 60 patients were diagnosed with a malignant tumor of anal canal. Among them, 25 cases involved anal adenocarcinoma, 26 cases referred to a squamous cell carcinoma and in 5 cases, Bowen disease was identified. Two melanomas, one GIST stromal tumor and one case of Paget disease, were recognized as well. It seems that in our center the frequency and prevalence of anal adenocarcinoma is increased compared to the results from international data. More studies involving larger series of patients are required in order to shed further light in the true incidence of anal cancer and it subtypes in Hellenic population.Techniques in Coloproctology 09/2011; 15 Suppl 1:S87-9. DOI:10.1007/s10151-011-0753-x · 1.34 Impact Factor
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ABSTRACT: Small cell carcinomas represent <1% of colorectal/anal carcinomas and have a poor prognosis. Anorectal squamous cell carcinomas are often associated with high-risk human papillomavirus (HPV) infection, similar to squamous and small cell carcinomas of the uterine cervix. In HPV infection, the oncoprotein E7 inactivates the tumor suppressor Rb, leading to p16 upregulation; however, in small cell carcinomas, the Rb pathway is often blocked by other mechanisms; thus, increased p16 may not indicate HPV infection. P16 immunohistochemistry (IHC) may have a limited role in evaluating small cell carcinomas for HPV infection. Formalin-fixed, paraffin-embedded tissue sections of previously diagnosed small cell carcinomas of the anus (n=5) and rectum (n=11) were subjected to IHC for p16, CDX2, and p63, followed by in situ hybridization for high-risk HPV. All (100%) cases of anal and rectal small cell carcinomas were positive for p16, and 100% of anal and 82% of rectal small cell carcinomas were positive for high-risk HPV. The majority of cases showed low or very low HPV copy numbers. In 6 cases, HPV was detected only by using the HPV-16 genotype-specific assay detecting very low copy numbers (1 to 2 viral copies). The majority of tumors expressed p63, which was more pronounced in the anal tumors. CDX2 expression was observed predominantly in rectal tumors. High-risk HPV can be detected using in situ hybridization in the majority of anorectal small cell carcinomas, which are uniformly p16 positive by IHC. HPV-targeted therapy could result in better control of these aggressive neoplasms.The American journal of surgical pathology 04/2012; 36(7):1087-92. DOI:10.1097/PAS.0b013e3182549b6d · 4.59 Impact Factor