Introduction Primary central nervous system pure germinoma (GE) has a favorable long-term survival because of its radiosensi- tivity. However, frequent involvement of the suprasellar region and the irradiation lead to permanent endocrine dys- function after treatment [1, 2, 5–7, 15–17]. To minimize endocrinological deterioration, chemotherapy alone or with low-dose radiation has been tried [7, 9, 14]. However, the methods of treatment have not yet been established and radiation therapy is still mandatory. Perioperative prediction of the hormones that will need to be replaced is important, especially in children who not only require basic hormones for the maintenance of life but will also continue to grow and will develop sexually. To treat hormonal imbalances, exact evaluation of hormonal status both before and after treatment is required. How- ever, the difficulties in the evaluation of preoperative hor- monal status hinder this kind of prediction, and the appro- priate method of predicting who will need hormonal re- placement and which hormones should be replaced is still unknown. The aim of this study is to propose a simple method of predicting the hormonal outcome after treatment of intracranial pure GEs. This method will be helpful for the endocrinological follow-up in children with GE who require radiation therapy. Child’s Nerv Syst (1999) 15:179–184 © Springer-Verlag 1999 ORIGINAL PAPER A simple method of predicting hormonal outcome in children with intracranial germinoma Do-Hyun Nam Kyu-Chang Wang Chung-Ho Shin Se-Won Yang Byung-Kyu Cho Abstract Even a small intracranial germinoma (GE) frequently pro- vokes pituitary hypofunction. We evaluated the relationships between preoperative hormonal status and hormonal outcome and between size of suprasellar mass and hormonal outcome in 22 children with intracra- nial pure GE to determine whether or not these can reflect the degree of hypothalamo-pituitary axis de- struction. Preoperative hormonal status was graded from I to IV ac- cording to the serum prolactin level (s-PRL) and thyroid function (TF). The hormonal outcome was esti- mated by the type and the number of hormonal replacement medications taken on the basis of the triple load test and endocrinological examina- tions at the time of the last follow-up (median period: 43 months). Fifteen of the 22 patients had suprasellar lesions. All 13 patients who had diabetes insipidus (DI) at presenta- tion needed desmopressin acetate (DDAVP) during the follow-up period. The correlation between in- crement of preoperative grade and the increment in the number of hor- mones to be replaced was statisti- cally significant (P < 0.05). This preoperative grading was a more reliable predictor than the size of suprasellar tumor. In conclusion, preoperative grading by s-PRL and TF test is useful for the prediction of posttreatment hormonal replacement in children with intracranial pure GE. Key words Intracranial germinoma · Prolactin · Thyroid function · Hormonal outcome Received: 10 July 1998 Revised: 30 August 1998 D.-H. Nam Department of Neurosurgery, Sung Kyun Kwan University College of Medicine, Samsung Medical Center, 50 Ilwon-dong, Kangnam-gu, Seoul 135-710, Korea K.-C. Wang · B.-K. Cho () Division of Pediatric Neurosurgery, Seoul National University Children’s Hospital, 28 Yongon-dong, Chongno-gu, Seoul 110-744, Korea Tel.: +82-2-760-2350 Fax: +82-2-747-3648 C.-H. Shin · S.-W. Yang Department of Pediatrics, Seoul National University Children’s Hospital, 28 Yongon-dong, Chongno-gu, Seoul 110-744, Korea