Merkel cell carcinoma (MCC) is a rare, aggressive neuroendocrine malignancy of the skin with an annual incidence in the United States of 0.34 and 0.17 per 100,000 men and women, respectively. MCC incidence increases with age, is higher among men and whites, and positively correlates with solar ultraviolet (UV) index, suggesting UV radiation exposure may play a role in the development of MCC. MCC incidence rates are also higher among severely immunosuppressed populations, including people who have undergone organ transplantation, have lymphoma, and are HIV-infected. Given the increased risk for MCC observed with immunosuppression and the established associations between viral infections and other cancers that occur more often in immunosuppressed populations, MCC was a prime cancer candidate for a viral cause. Subsequent investigation discovered a genome encompassing 5387 base pairs of a new polyomavirus, subsequently named the Merkel cell polyomavirus.
Dana E. Rollison, Anna R. Giuliano and Jürgen C. Becker
Edward E. Partridge, Nadeem R. Abu-Rustum, Susan M. Campos, Patrick J. Fahey, Michael Farmer, Rochelle L. Garcia, Anna Giuliano, Howard W. Jones III, Subodh M. Lele, Richard W. Lieberman, Stewart L. Massad, Mark A. Morgan, R. Kevin Reynolds, Helen E. Rhodes, Diljeet K. Singh, Karen Smith-McCune, Nelson Teng, Cornelia Liu Trimble, Fidel Valea and Sharon Wilczynski
Overview Despite a significant decrease in the incidence and mortality of cervical carcinoma in the United States, an estimated 12,200 women will be diagnosed with the disease in 2010, with 4210 expected deaths.1 High-risk groups include women without access to health care and those who have immigrated to the United States from countries where cervical cancer screening is not routinely performed.2 Because cervical cytology screening is the current method for early detection of this neoplasm, the purpose of these guidelines is to provide direction for the evaluation and management of cervical cytology. These guidelines include recommendations on screening techniques, initiation, and frequency of screening, and management of abnormal screening results including colposcopy. Cervical cytology screening techniques include liquid-based cytology or conventional Papanicolaou (Pap) smears. Unless specifically noted, these techniques are collectively referred to as cervical cytology in this discussion. Human papillomavirus (HPV) DNA testing for primary cervical cancer has been approved by the FDA; several diagnostic tests are available (e.g., HPV high-risk and HPV 16/18 DNA tests, Hybrid Capture 2 HPV DNA test). However, HPV DNA testing is not recommended in women younger than 21 years.3 HPV DNA testing for high-risk virus types can also be used as a component of both primary screening and workup of abnormal cytology results; it is not useful to test for low-risk virus types.3 (See HPV DNA Testing on page 1378 for more detail about these tests.) Colposcopy, along with colposcopically directed biopsies, is the primary method for evaluating women with abnormal cervical cytologies....