Parvovirus and thyroid cancer.

Parvoviruses are some of the smallest DNA viruses known to infect a wide range of animal species and humans. Though not all parvoviruses are pathogenic, some can cause disease ranging from asymptomatic to benign to life-threatening. Recently, there has been an interest in the possible role of parvoviruses in thyroid disease in general. The objectives of this review are to cite and appraise the available evidence on the role of parvoviruses in thyroid cancer in particular. Little to no evidence is available directly linking animal parvoviruses and thyroid cancer, but there is a growing literature on the human erythrovirus B19 (EVB19) and its association with thyroid cancer. Of particular interest is the persistence and expression of EVB19 DNA, RNA, and protein in a wide variety of thyroid tissues. While a causative role of EVB19 in the pathogenesis of thyroid cancer cannot be supported at this time, an indirect role is hypothesized and discussed but with the recognition that the data are limited. Further studies are clearly warranted to determine the exact, if any, role of this human pathogen in thyroid cancer.