抄録
A 13.5-year-old girl who developed puberty due to HCG production by suprasellar ectopic pinealoma was reported. This girl appeared to be in a state of precocious puberty at the age of 5 when ectopic pinealoma was first diagnosed. Her breasts started to develop at 13 years of age in spite of hypopituitarism. Plasma LH was found to increase for several months and gave rise to suspicion of the recurrence of the tumor, which was confirmed by the detection of HCG in plasma and CSF. Precocious puberty or pubertycan be a characteristic endocrinological manifestation of an HCG producing tumor not only in boys but also in girls. The measurement of plasma HCG (or LH) can be a useful tumor marker in following the clinical course of an HCG producing tumor.