Ectopic intracranial germinoma

The role of neurosurgeon in the multidisciplinary approach to ectopic or bifocal intracranial germinoma: A systematic review and report of two illustrative cases

BACKGROUND

Pure germinoma typically originates from the midline and is usually found in the pineal and suprasellar regions in 76-90 % of cases. When it is in both regions, it is considered bifocal (10 % at diagnosis). If pure germinoma is located outside of the midline, it is considered ectopic, with a global incidence of about 0.7 %. The study aims to describe the clinical and surgical approach to patients with atypical intracranial ectopic germinoma (IEG) and bifocal germinoma (BG) through a literature review with the goal to delineate the correct diagnostic and therapeutic pathway, to reduce the diagnostic delay and improve the prognosis of these patients.

METHODS

A systematic review of the literature in most common electronic database (PubMed, Ovid MEDLINE and Ovid EMBASE) on IEG and BG, in according with the "PRISMA statement" criteria, from January 1990 to September 2022 was done. In addition, two rare cases of IEG and BG were reported.

RESULTS

This systematic review included 16 papers (20 patients) with a final diagnosis of IEG and 30 papers (121 patients) with a final diagnosis of BG. IEGs seems to involve primary basal ganglia (40 %) and corpus callosum (40 %). For IEGs, biopsy (70 %, 14 cases out of 20) was the most common surgical approach: open approach (35 %), stereotactic minimally invasive approach (30 %) or endoscopic trans-sphenoidal approach (5 %). Partial resection was performed in 10 % of cases, whereas a total resection was performed in 20 % of cases. Also for BGs, biopsy was the most common surgical approach in 80 % of patients, whereas surgical resection (partial or total) was performed in 5.3 % of patients.

CONCLUSION

IEG and BG are rare type of primary intracranial germ cell tumor, whose unusual location often can cause delays in diagnosis, which can have a significant impact on the patient's prognosis and requiring a multidisciplinary and timely approach.

Update on MRI in pediatric intracranial germ cell tumors-The clinical and radiological features

Intracranial germ cell tumors (iGCTs) are uncommon brain tumors that mainly occur in children. Differing in histology, location, and gender of the patients, iGCTs are often divided into germinomas and non-germinomatous germ cell tumors (NGGCTs). Early diagnosis and timely treatment are crucial to iGCTs, the subtypes of which have substantial variations. This review summarized the clinical and radiological features of iGCTs at different sites, and reviewed the recent advances in neuroimaging of iGCTs, which can help predict tumor subtypes early and guide clinical decision-making.

Factors Influencing Craniospinal Relapse of Intracranial Germinoma After Complete Remission

OBJECTIVE

To evaluate the pathomechanism of the recurrence of intracranial germinoma after complete response and to confirm the association of the initial magnetic resonance imaging and therapeutic factors with recurrence.

METHODS

This study included patients who were followed up for ≥5 years and who were treated in our hospital from 1980 to 2021. Those with germinoma and germinoma with syncytiotrophoblastic giant cells were diagnosed pathologically. Data were categorizedbased on "gender," "single region," "intraventricular dissemination at the initial diagnosis," "hydrocephalus," "types of radiation therapy (RT)," and "chemotherapy." Fisher's exact probability test was used to assess differences between the no recurrence and recurrence groups.

RESULTS

Among 43 patients, 34 had no recurrence, 5 had delayed recurrence (≥60 months), and 4 had early recurrence (<60 months). Follow-up periods were 143.5 (60-380), 198 (88-222), and 132.5 (75-291) months for the no recurrence, delayed recurrence, and early recurrence groups, respectively. Five patients with delayed recurrence showed 3 intracranial lesions and 2 spinal lesions. Four patients with early recurrence showed 3 intracranial lesions and 1 spinal lesion. Differences in delayed recurrences (focal RT vs. RT including whole-ventricle system; P = 0.0491) were significant in Fisher's exact test.

CONCLUSIONS

RT including the whole-ventricle system reduces delayed craniospinal relapses including dissemination, local, and distant recurrences even ≥5 years after complete response in patients with primary central nervous system germinoma.

Ectopic Germinoma: A Delayed Diagnosis With Serial Magnetic Resonance Imaging Features

Germinoma arising from intracranial off-midline structures is considered ectopic. Although basal ganglia germinoma is a rare occurrence, it is more commonly seen in the Asian population, particularly among boys. Here, we report a case of an adolescent boy who presented with hemiplegia and delayed diagnosis of basal ganglia germinoma with progression on serial magnetic resonance imaging (MRI). Several signal changes have been described during the early stage of the disease such as T2-weighted patchy hyperintense signal, cerebral hemiatrophy, and signal change on susceptibility-weighted imaging. ¹¹C-methionine positron emission tomography is an additional imaging technique that can reveal ectopic germinoma. Follow-up MRI revealed small cystic changes, and the latest imaging showed progression into a large multicystic lesion with mass effect. The patient underwent surgery, and histopathological examination revealed basal ganglia germinoma. We highlight the serial MRI changes that were suggestive of basal ganglia germinoma in this case.

Unusual presentation of the germinoma: A 26-year-old female

Background:

Germinoma is a rare lesion found commonly in the pineal and suprasellar regions of the brain. Clinical presentation mainly involves the location and size of the tumor and the patient age. Endocrine abnormalities are the most common symptom.

Case Presentation:

The patient was a 26-year-old Iranian female who suffered from germinoma for a long time and was referred to Loghman Hakim Hospital for amenorrhea, polyuria, and polydipsia. Despite diagnostic challenges, she was finally diagnosed with suprasellar germinoma after endoscopic transsphenoidal surgery, followed by radiotherapy and medical interventions to complement the surgery.

Conclusion:

It is important to be able to diagnose the patient's problem at an early stage based on their history, hormonal profile, laboratory results and radiological view.

Molecular Pathology and Targeted Therapies for Personalized Management of Central Nervous System Germinoma

Intracranial germinomas are rare tumours, usually affecting male paediatric patients. They frequently develop in the pineal and suprasellar regions, causing endocrinological disturbances, visual deficits, and increased intracranial pressure. The diagnosis is established on magnetic resonance imaging (MRI), serum and cerebrospinal fluid (CSF) markers, and tumour stereotactic biopsy. Imaging techniques, such as susceptibility-weighted imaging (SWI), T2* (T2-star) gradient echo (GRE) or arterial spin labelling based perfusion-weighted MRI (ASL-PWI) facilitate the diagnosis. Germinomas are highly radiosensitive tumours, with survival rates >90% in the context of chemoradiotherapy. However, patients with resistant disease have limited therapeutic options and poor survival. The aim of this review is to highlight the genetic, epigenetic, and immunologic features, which could provide the basis for targeted therapy. Intracranial germinomas present genetic and epigenetic alterations (chromosomal aberrations, KIT, MAPK and PI3K pathways mutations, DNA hypomethylation, miRNA dysregulation) that may represent targets for therapy. Tyrosine kinase and mTOR inhibitors warrant further investigation in these cases. Immune markers, PD-1 (programmed cell death protein 1) and PD-L1 (programmed death-ligand 1), are expressed in germinomas, representing potential targets for immune checkpoint inhibitors. Resistant cases should benefit from a personalized management: genetic and immunological testing and enrolment in trials evaluating targeted therapies in intracranial germinomas.

A Rare Case of a Pediatric Medullary Intracranial Germinoma

BACKGROUND

Germinomas are rare intracranial lesions, with medulla germinomas being reported in only approximately 20 cases to date. These tumors are extremely sensitive to radiotherapy, and knowledge of them can allow for accurate diagnosis as well as significantly impact treatment and prognosis.

CASE DESCRIPTION

We present a case of medullary germinoma and review the cases previously reported in the literature.

CONCLUSIONS

A few imaging characteristics are noted in multiple cases, such as cystic components, enhancement, and absence of hydrocephalus. These features can provide clues to diagnosis of this rare entity.

Bifocal germinoma of the septum pellucidum and the sellar-supra-sellar region: An uncommon presentation for a rare tumor

Intracranial germinomas (IGs) are rare malignant germ cell tumors. The septum pellucidum (SP) is an extremely rare site of IGs. To our knowledge we report the first patient presenting with synchronous involvement of the SP and the sellar region. A 28-year-old woman presented with unsteady gait, mild left motor deficit, polydipsia and polyuria of 2-month duration. Imaging revealed a multicystic butterfly lesion in the SP extending to the frontal lobes, with unusual CT and MRI features, associated with a sellar area lesion. A navigation-guided biopsy revealed a pure germinoma. MRI at 12 months after the completion of the radiation therapy showed the resolution of the lesions. She achieved complete remission at 8-year follow-up. IG arising in the SP is rare but should be considered in the differential diagnosis, especially in young adult and particularly in male, presenting with multi-cystic lesion. The presence of a synchronous mass is a clue for the presumptive diagnosis of germinoma. These findings suggest that IG in SP may present as a large tumor with large cysts and may look as central neurocytoma. ADC value is helpful to differentiate them.

Suprasellar Germinomas: 2 Case Reports and Literature Review

BACKGROUND

Germinomas are rare malignant central nervous system tumors, a type of germ cell tumor, according to the 2016 World Health Organization Classification of Brain Tumors. Most of these tumors develop along the midline, most often from the pineal gland, followed by tumors arising in the suprasellar cisterns. Suprasellar germinomas commonly manifest with diabetes insipidus, visual impairment, and hypothalamic-pituitary failure. We present a literature review from the PubMed database and report 2 cases of suprasellar germinomas.

CASE DESCRIPTION

Both pediatric patients presented with progressive visual loss; one did not show endocrinologic impairment, and the other presented with hypothyroidism, diabetes insipidus, and generalized edema. Magnetic resonance imaging showed expansive suprasellar masses in both cases, confirmed as germinomas at histopathologic examination. The patients were treated with the same surgical approach, although their outcomes were different because of endocrinologic and post surgical complications.

CONCLUSIONS

Suprasellar germinomas are highly curable lesions when diagnosed early. The treatment remains controversial and should be individualized, but the association of chemotherapy and radiotherapy allows reduce adverse effects and shows great results.