Effects of puberty on bone age maturation in a girl after medulloblastoma therapy

Resolution of precocious puberty following resection of fourth ventricular medulloblastoma: case report

Medulloblastoma is a malignant embryonal tumor that arises in the cerebellum and invades the fourth ventricle, often resulting in obstructive hydrocephalus. Patients typically present with symptoms related to increased intracranial pressure and cerebellar dysfunction. The authors report a rare case of classic medulloblastoma with central precocious puberty (CPP) as its only presenting symptom. A 7-year-old boy with no prior history of medulloblastoma presented with Tanner Stage IV testicular enlargement and a 4-month history of acne and pubic hair. Laboratory tests of blood samples demonstrated highly elevated luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone. Admission MRI of the brain revealed a mass in the posterior fossa, which bordered and compressed the fourth ventricle. The patient also exhibited mild lateral and third ventriculomegaly. Surgical options were discussed with the neurosurgical department. A suboccipital craniotomy and C-1 laminectomy were performed. A large mass was seen arising from the inferior surface of the vermis, and lying within the fourth ventricle. Gross-total microsurgical resection of the mass was performed. Histopathological investigation characterized the tumor as classic medulloblastoma. Follow-up laboratory tests of blood samples demonstrated a reduction of LH, FSH, and testosterone back to prepubertal levels. The patient then began radiation and chemotherapy. This report demonstrates that mild obstructive hydrocephalus due to a posterior fossa tumor may present with unexpected symptoms, such as CPP. To the authors' knowledge, precocious puberty has not yet been associated with medulloblastoma, although it has been found with other posterior fossa tumors. Extensive imaging of the CNS for patients presenting with CPP is recommended.

Endocrine outcome in children with medulloblastoma treated with 18 Gy of craniospinal radiation therapy

Craniospinal radiation therapy (CSRT) combined with chemotherapy results in significant endocrine morbidity. Between 1987 and 1990, a trial using 18 Gy was conducted to treat 10 young children with medulloblastoma. There were 7 survivors. We compared the endocrine outcome in these children (group 18 Gy) to that of a comparable group treated with conventional doses of CSRT that ranged from 23 to 39 Gy (group CD). Both groups had an identical history of chemotherapy and tumor stage and were treated with recombinant growth hormone therapy (rhGH). The mean age of group 18 Gy at diagnosis was 4.0 years, and rhGH treatment was initiated in 6 children at age 9.2 years. Group CD (12 children) was diagnosed at a mean age of 5.8 years and rhGH started in 11 children at a mean age of 9.6 years. The dose of rhGH used in both groups was identical (0.3 mg/kg/wk). For group 18 Gy, adult heights and sitting heights (a mean standard deviation score of -1.01 +/- 1.11 and -1.62 +/- 1.16, respectively) were statistically greater (P < 0.05) than those for group CD (mean standard deviation score of -2.04 +/- 0.83 and -3.16 +/- 1.43, respectively). Moreover, adult heights of group 18 Gy were not different from midparental heights, unlike group CD, whose adult heights were less than midparental heights (P < 0.0001). Of other endocrine sequelae, 10 patients of the CD group were hypothyroid, 3 had adrenal insufficiency, 3 had hypogonadism, and 2 had early puberty. In contrast, within group 18 Gy, only 1 was hypothyroid (P = 0.006) and 1 had early puberty. We conclude that endocrine morbidity was significantly reduced with 18 Gy CSRT in young children with medulloblastoma.