Germ cell tumors arise from the malignant transformation of germ cells. They most commonly occur in the intracranial pineal and sellar regions, typically affecting individuals aged 10 to 25. Clinical manifestations vary significantly depending on the tumor location;common symptoms include diabetes insipidus, visual disturbances, and elevated intracranial pressure.
Global incidence of germ cell tumors by country
Intracranial germ cell tumors account for approximately 3%–8% of pediatric intracranial tumors, with a higher incidence observed in Asian populations.In males, these tumors are most commonly found in the pineal region, whereas in females, they are most frequently located in the sellar region.Dual lesions involving both the sellar and pineal regions occur in 5%–25% of patients.Germ cell tumors are sensitive to radiotherapy and chemotherapy, and the prognosis is relatively favorable.
Symptoms associated with germ cell tumor stages
1.Early symptoms of germ cell tumor
The tumor is small, with mild and atypical symptoms.Tumors in the pineal region may cause mild headache, while those in the sellar region may present solely as polydipsia and polyuria, easily leading to misdiagnosis as common diabetes insipidus or encephalitis.
2.Intermediate-stage germ cell tumor symptoms
Tumors in the pineal region present with distinct symptoms of Parinaud syndrome and hydrocephalus, while those in the sellar region present with the classic triad of diabetes insipidus, visual impairment, and hypopituitarism.
3.Advanced germ cell tumor symptoms
Tumor disseminates widely with cerebrospinal fluid (CSF) seeding, causing severe intracranial hypertension, damage to multiple cranial nerves, impaired consciousness, and systemic failure.
When to Seek Medical Attention
Early signs of germ cell tumors include excessive thirst and urination, vision loss, headaches, and delayed sexual development.Please consult a doctor via the "Chat with a Doctor" feature to facilitate early detection.During the online consultation, the doctor will ask about the child's symptoms and development, and guide you through procedures such as a cranial MRI and tumor marker tests.
Staging of germ cell tumors
Germ cell tumor: Stage 0
This staging system is not applicable to germ cell tumors.Germ cell tumors are assessed using a metastasis risk evaluation based on tumor markers, the extent of dissemination, and the tumor site.
Germ cell tumor: Stage I
The tumor is confined to the primary site with no evidence of dissemination; symptoms are mild and primarily related to local compression.
Germ cell tumor: Stage II
The tumor involves cerebrospinal fluid dissemination or local lymph node involvement, presenting with multiple symptom clusters, yet remains confined to the central nervous system.
Germ cell tumor: Stage III
Tumor disseminates widely to the ventricular system or spinal cord, causing severe intracranial hypertension and multifocal neurological deficits.
Germ cell tumor: Stage IV
Tumor metastasis to sites outside the central nervous system (e.g., lungs, bones), presenting with corresponding metastatic symptoms.
Detailed Symptoms of Germ Cell Tumors
1.Onset of diabetes insipidus
The most common early symptom of a germ cell tumor in the sellar region is excessive thirst and polyuria (with daily urine output reaching several liters), caused by insufficient antidiuretic hormone secretion resulting from damage to the hypothalamic-pituitary axis.
2.Changes in vision and visual field
Tumor compression of the optic chiasm causes decreased visual acuity and bitemporal visual field defects; severe cases may lead to blindness. This is a key clinical manifestation of germ cell tumors in the sellar region.
3.Abnormal sexual development
Pineal region tumors can cause precocious puberty, whereas tumors in the sellar region lead to delayed pubertal development, lack of sexual characteristics, and stunted growth.
4.Increased intracranial pressure
Tumors in the pineal region compress the cerebral aqueduct, causing hydrocephalus and symptoms of increased intracranial pressure such as headache, vomiting, and papilledema.
5.Ocular motility disorder
Compression of the superior colliculus by a pineal region tumor causes Parinaud syndrome, manifesting as an inability to look upward and pupillary dilation or anisocoria.
6.Weakness in hemiplegic limbs
Early manifestations of germ cell tumors in the basal ganglia region include progressive hemiparesis, which begins in one upper or lower limb and gradually worsens.
7.Decline in cognitive function
Tumor compression or infiltration leads to memory loss, impaired concentration, and cognitive decline, affecting learning ability.
8.Short stature
Hypopituitarism leads to insufficient growth hormone secretion; in children, this manifests as short stature and stunted growth and development.
9.Ataxia
Tumor compression of the superior cerebellar peduncle or the superior vermis leads to truncal ataxia, nystagmus, and unsteady gait.
Conclusion
Germ cell tumors are highly sensitive to radiotherapy and chemotherapy, and early diagnosis and treatment can lead to a favorable prognosis.Testing for tumor markers such as AFP and β-HCG is significant for diagnosis and differential diagnosis.
