LAUSR

Sacrococcygeal teratomas (SCT) were first described by Virchow in 1869 and, because of their complexity, were called “monstrous tumor”. They represent the most common germcell tumors of childhood, with an incidence of approximately 1 in 35 000–40 000 live births, and a female preponderance of 3:1. Although most cases diagnosed at the time of birth are mature/immature teratomas, yolk sac tumors occur more frequently in children after 1 year of age, reportedly occurring at a rate of ≥75%. The Altman classification is commonly used for classification according to the occurrence site. Sacrococcygeal teratomas diagnosed postnatally have been associated with an excellent prognosis after surgical excision. In contrast, fetuses with a prenatally diagnosed SCT still have a high risk of death even if the prenatal diagnosis may have contributed to improvement of outcome. The main reason for the poor prognosis in fetal SCT is high-output cardiac failure caused by increased blood flow, according to the amount of solid component present in the tumor, and rupture of the tumor during delivery with a massive hemorrhage. Few large multicenter surveys on both the prenatal and postnatal courses of SCT have been performed. In 2009, the Japanese SCT Study Group was established with the support of a grant from The Ministry of Health, Labour and Welfare of Japan (H21-23 Health and Labour Sciences Research Grants for Research on Intractable Diseases). A nationwide retrospective cohort study was conducted on 97 fetuses prenatally diagnosed with SCT between 2000 and 2009. As a result, the overall mortality of prenatally diagnosed SCT excluding terminations was 16%. Early delivery, predominantly solid component tumors, and histological immaturity were associated with an increased risk of mortality. Unfortunately, no clear medical guidelines for SCT have yet been established because SCT is very rare and there are few opportunities to encounter this disease, not only for pediatricians and obstetricians but also for pediatric surgeons. Therefore, there is insufficient information concerning the risk factors of severity, optimal mode of delivery, treatment strategies and appropriate follow-up assessment for general physicians without expert credentials. The Japanese SCT Study Group, supported by a grant from The Ministry of Health, Labour and Welfare of Japan (H26-28, H29-31 Health and Labour Sciences Research Grant for Research on Intractable Diseases), has now established a set of guidelines for SCT. The guidelines have been developed using the methods described in the Medical Information Network Distribution System (Minds) Handbook for Clinical Practice Guideline and the Minds Manual for Clinical Practice Guideline Development. In this issue, we are introducing the first guidelines for SCT to be established in Japan as well as in the world, and they may have huge clinical value and significance in terms of developing treatment strategies and follow up. The guidelines will potentially contribute to the improvement of the prognosis and quality of life of SCT patients.