PRECOCIOUS PUBERTY IN A GIRL WITH AN HCG-SECRETING SUPRASELLAR IMMATURE TERATOMA

Although precocious puberty is common in boys with human chorionic gon adotropin (hCG)-secreting brain tumors, it is extremely rare in girls. The authors describe a 6-year-old girl with an hCG-secreting suprasel lar immature teratoma who presented with diabetes insipidus, increased intracranial pressure, and precocious puberty, On admission, breast b udding was observed. The serum hCG level was 1230 mIU/ml. Both luteini zing hormone (LH) and follicle-stimulating hormone (FSH) remained belo w detectable levels, even after gonadotropin-releasing hormone stimula tion. Serum estrogen and androgen were moderately elevated. After chem otherapy, breast budding disappeared with normalization of serum hCG. It has been believed that hCG does not produce precocious puberty in g irls in the absence of FSH, and this has been used as an explanation f or the rarity of precocious puberty in girls with hCG-secreting brain tumors. However, it has also been reported that hCG has not only LH ac tivity but also intrinsic, although weak, FSH-like activity. In the pr esent case, this FSH-like activity was considered to have played a rol e in the development of precocious puberty. It is speculated that a ve ry high level of serum hCG can produce precocious puberty in girls. Th e rarity of intracranial germ-cell tumors with a high potential of hCG secretion may be one of the reasons why hCG-induced precocious pubert y is uncommon in girls.