Intracranial germ cell tumors

Present by R3 吳孟庭

Youmans neurological surgery fifth edition

Chapter 231

Classsification of intracranial germ cell tumor Benign: Mature teratoma

Malignant: Germinoma (60%) Embryonal carcino

ma/endodermal sinus tumor

Choriocarcinoma Immature teratoma

Epidemiology

Intracranial GCTs represent approximately 2-5 percent of all intracranial tumors in Japan.

GCTs (particularly germinomas) are more common in some Asian countries, where they account for 12 percent of all intracranial neoplasms.

In Western countries, the incidence is much lower, representing 0.5 percent of intracranial tumors.

Incidence

Male : female=2:1Male70% are found in the pineal regio

nFemale75% are localized to the supra

sella regionIntracranial GCTs peak in incidence bet

ween 10 and 14 years of age.

Clinical presentation

The presenting signs and symptoms are dependent upon tumor location.

Headache, nausea, vomiting, and lethargy (from increased intracranial pressure in patients with pineal lesions)

Diplopia, hypopituitarism or diabetes insipidus (with suprasellar tumors)

Paralysis of upward conjugate gaze (Parinaud's syndrome)

Parinaud's syndrome known as Dorsal Midbrain Syndrome or

Pretectal Syndrome Secondary to midbrain tectal compression It is a cluster of abnormalities of

eye movements and pupil dysfunction, characterized by:

1. Paralysis of upgaze 2. Pseudo-Argyll Robertson pupils (light-

near dissociation) 3. Convergence-Retraction nystagmus 4. Eyelid retraction (Collier's sign)

Image Features

Germinoma: homogeneous, isointense; may appear cystic or solid

Teratoma: heterogeneous, calcification; presence of fat

figure 231-6. A, Sagittal enhanced MRI scan of endodermal sinus tumor showing heterogeneous enhancement and cyst. B, Same patient, axial view.

Tumor marker

PLAP: placental alkaline phosphatase; HCG: human chorionic gonadotropin; AFP: alpha-fetoprotein

Tumor type Marker profile

Germinoma PLAP

Choriocarcinoma HCG

Embryonal carcinoma HCG+AFP

Endodermal sinus tumor

AFP

Pathology- histogenesis Primordial germ cells

become disseminated widely throughout the embryo.

Failure of the normal involution of these migrated totipotent cells leaves rests of cells that are susceptible to neoplastic transformation.

Tumor Location

Intracranial germ cell tumor arise in the midline

Pineal (50%) Suprasella (30%) basal ganglia, posterior fossa, pituitar

y gland..(10%)

Germinoma Microscopically, irregularly sized lobul

es of neoplastic cells may be divided by thin connective tissue septa

Large, round neoplastic cell with a large central nucleus are intermixed with lymphocytes

Germinoma Strong KIT expression was found in th

e cell membrane of germinomas. C-kit gene mutation: common and wi

dely distributed in intracranial germinomas

Journal of Neurosurg. 2006 Mar;104(3 Suppl):173-80.

Endodermal Sinus Tumor (Yolk Sac Carcinoma) and Embryonal Carcinoma

Distinction between—unclear Interchangeable AFP(+)

Choriocarinoma Rarest An overwhelming tendency to arise in

the pineal region of males. Syncytiotrophoblasts HCG(+)

Teratoma Consist of tissues derived from all

three germ cell layers Mature: well-defined, cartilage,

bone and hair Immature: less well-defined and

locally invasive, more central areas of hemorrhage and necrosis

Commonest tumor found in neonates

Operative management

CSF study-germ cell marker Debulking of tumor

Postoperative management

Radiation therapy Germinomas are exquisitely radiosens

itive Fractionated external beam irradiatio

n Gamma knife radiosurgery Surg Neurol. 2006 Apr;65(4):343-51

Postoperative management Low-dose prophylactic craniospinal r

adiotherapy for intracranial germinoma

Low-dose CSI was administered in 29 patients: usually 21 Gy of CSI, 9.0 Gy of ventricular boost, and a 19.5-Gy tumor boost, all at 1.5 Gy per fraction.

Int J Radiat Oncol Biol Phys. 2006 Jun 1;65(2):481-5. Epub 2006 Mar 10

Chemotherapy

Cisplatin VP-16 C/T in the initial treatment of patient

with nongerminomatous germ cell tumors—relative radioresistance

Survival

Germinoma-90 percent at 10 years Nongerminomatous germ cell tumor–

less than 25percent of 5-year survival rate

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