Prognosis
In keeping with their assignment as WHO grade 1, pilocytic astrocytoma is not usually associated with recurrence after complete resection. The pilomyxoid astrocytoma variant may behave more aggressively than classic pilocytic astrocytoma, but this might also be associated with the younger age at presentation and their more frequent midline location. In cases of progressive/recurrent disease or when maximal surgical removal has been achieved but some residual tumor remains, chemotherapy and/or radiation therapy may be considered by the medical team. Incidence
Regularly updated statistics about the incidence, epidemiology, and survival outcomes of brain tumors can be found in the annual reports of the Central Brain Tumor Registry of the United States (CBTRUS). These figures suggest that an average of just over 1,000 pilocytic astrocytomas are diagnosed per year in the US, representing about 1% of all CNS tumors. In children, however, the proportion is much higher. Pilocytic astrocytoma is the single most common childhood brain tumor, accounting for almost 20% of brain tumors diagnosed in 0-14 year-olds, with a peak incidence between 5–14 years of age. Additional images
References


== External links ==
If the gestational age as calculated from an early ultrasound is contradictory to the one calculated directly from the last menstrual period, it is still the one from the early ultrasound that is used for the rest of the pregnancy. In case of in vitro fertilization, calculating days since oocyte retrieval or co-incubation and adding 14 days.Gestational age can also be estimated by calculating days from ovulation if it was estimated from related signs or ovulation tests, and adding 14 days by convention.A more complete listing of methods is given in following table:
As a general rule, the official gestational age should be based on the actual beginning of the last menstrual period, unless any of the above methods gives an estimated date that differs more than the variability for the method, in which case the difference cannot probably be explained by that variability alone.