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.
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ABSTRACT: Melanoma of the anal cavity is an uncommon malignant tumor with an aggressive clinical behavior. The presence of nonmelanocytic cell or tissue components, designated as divergent differentiation, is an unusual but well-documented phenomenon in melanoma. We experienced a rare case of amelanotic melanoma with neuroendocrine differentiation of the anal canal, occurring in a 68-year old woman. This tumor was characterized by a clear-cut radial growth phase and an invasive component composed of a diffuse small cells population positive for neuroendocrine markers with a focal but convincing co-expression of S100 protein. To the best of our knowledge, this represents the first case of neuroendocrine differentiation in a primary melanoma of the anal cavity. Although anal melanoma with neuroendocrine differentiation is exceptional, clinical practitioners should be aware of its possibility at this site. © The Author(s) 2015.International Journal of Surgical Pathology 02/2015; 23(4). DOI:10.1177/1066896915573568 · 0.96 Impact Factor
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ABSTRACT: Squamous cell carcinomas of the lower anogenital tract that are related to human papillomavirus (HPV) infection represent a significant disease burden worldwide. The diagnosis and management of their noninvasive precursors has been the subject of extensive study and debate over several decades, accompanied by an evolving understanding of HPV biology. Recent new consensus recommendations for the pathologic diagnosis of these precursor lesions were published in 2012, the result of the Lower Anogenital Squamous Terminology project cosponsored by the College of American Pathologists and the American Society for Colposcopy and Cervical Pathology. Most salient among the new guidelines are the recommendation to switch to a 2-tiered nomenclature (high-grade squamous intraepithelial lesion and low-grade squamous intraepithelial lesion) rather than the traditional 3-tiered "intraepithelial neoplasia" terminology, and the recommendation to expand use of the immunohistochemical marker p16 to distinguish between low-grade squamous intraepithelial lesion and high-grade squamous intraepithelial lesion/intraepithelial neoplasia 2. The goals of the project were to align diagnostic terminology with our knowledge of HPV biology, increase reproducibility, consolidate diverse systems of nomenclature, and ultimately better determine a patient's true cancer risk. The clinical guidelines for screening and management of cervical intraepithelial neoplasia have also been recently updated, most notably with a lengthening of screening intervals. In this review, we focus on the new guidelines put forth for pathologic diagnosis of HPV-related anogenital neoplasia, with discussion of the evidence behind them and their potential implications. We also provide an update on relevant biomarkers, clinical recommendations, and the newest developments relating to cervical neoplasia.