Table 1.

Causes of gonadotropin-dependent precocious puberty.

(i) Idiopathic

(ii) Central nervous system tumors (through direct or indirect effects on GnRH):

(1) Arachnoid cysts

(2) Craniopharyngiomas

(3) Ependymomas

(4) Germinomas (non-HCG secreting)

(5) Low-grade gliomas (juvenile pilocytic astrocytomas; optic pathway gliomas)

(iii) Paraneoplastic conditions (through the action of HCG on the LH receptor):

(1) Germ cell tumors:

(a) CNS

(b) Gonadal

(c) Hepatic

(d) Mediastinal (can occur in Klinefelter's syndrome)

(2) Hepatoblastoma

(iv) Developmental anomalies (through direct or indirect effects on GnRH):

(1) Arachnoid cysts

(2) Hydrocephalus

(3) Hypothalamic hamartomas

(v) Postirradiation (through direct effects on GnRH):

(1) Radiation therapy for childhood cancers (girls more susceptible)

(vi) Post-infectious, trauma, and bleed (through direct or indirect effects on GnRH):

(1) Sometimes associated with arachnoid cyst development

GnRH, gonadotropin releasing hormone; HCG, human chorionic gonadotropin; LH, luteinizing hormone.