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Ji Hoon Phi, Seung-Ki Kim, Sung-Hye Park, Seok Ho Hong, Kyu-Chang Wang and Byung-Kyu Cho

Object

Immature teratomas of the central nervous system (CNS) are rare neoplasms. Although adjuvant therapy is generally recommended after resection, the exact role of each therapeutic modality is not yet established. The purpose of this study was to analyze the clinicopathological correlation and the role of resection to define the optimal treatment modalities for immature teratomas of the CNS.

Methods

Between 1987 and 2002, eight patients underwent radical surgery for a lesion diagnosed as a CNS immature teratoma at the authors' institution. The clinical courses of these patients and the pathological features of their tumors were retrospectively reviewed.

Gross-total resection (GTR) was achieved in six patients at the initial operation. The mean follow-up period was 75 months. Two patients received postoperative adjuvant therapies and two patients did not, against medical advice. None of the four patients experienced recurrence after long-term follow up. Another four patients, all of whom underwent GTR of the tumor, did not receive adjuvant therapy as part of a prospective treatment scheme. One of them exhibited early recurrence and metastasis. The tumor had pathological features denoting a high-grade (Norris Grade III) lesion and neurocytomatous differentiation.

Conclusions

Aggressive resection seems to be of utmost importance in the treatment of immature teratomas of the CNS. Adjuvant chemotherapy and radiotherapy can be deferred if GTR is achieved in low-grade, immature teratomas, but adjuvant therapies may be warranted for high-grade ones.

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Do-Hun Lee, Eun Young Kim, Sepill Park, Ji Hoon Phi, Seung-Ki Kim, Byung-Kyu Cho, Jinho Lim and Kyu-Chang Wang

Object

The authors previously reported that human embryonic stem cells (hESCs) injected into the amniotic cavity of chick embryos immediately after neural tube incision in a surgically induced spinal open neural tube defect (ONTD) model promote the reclosure capacity of neural tubes. To simulate more closely the clinical situation of human ONTDs, in which a ssubstantial time period elapses before the prenatal diagnosis of spinal ONTDs, the authors investigated whether this reclosure capacity remains enhanced by the intraamniotic injection of hESCs at 24 hours after ONTD induction.

Methods

One hundred twenty-two chick embryos with ONTDs were randomly assigned to two groups: the control group (59 embryos) and the hESC-injection group (hESC group, 63 embryos). After the neural tubes of both groups had been opened, the hESC group underwent direct intraamniotic injection with hESCs marked with an enhanced green fluorescent protein at 24 hours after ONTD induction. The lengths of the remnant ONTDs were measured and the presence of hESCs was determined at 4, 6, and 8 days after ONTD induction. No difference in survival rates was observed between the two groups. The mean length of the ONTDs, adjusted for body length at the time of death and initial lesion length, was significantly shorter in the hESC group than in the control group (p < 0.001). No hESCs were found within reclosed neural tubes; rather, they covered the defect area during the reclosure process.

Conclusions

The authors demonstrate that hESCs injected into the amniotic cavity at 24 hours after ONTD induction enhance reclosure ability in chick embryos.

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Ji Hoon Phi, Sun Ha Paek, Hyun-Tai Chung, Sang Soon Jeong, Chul-Kee Park, Hee-Won Jung and Dong Gyu Kim

Object

The current study was undertaken to evaluate the tumor control rate and functional outcome after Gamma Knife surgery (GKS) in patients with a trigeminal schwannoma. The conditions associated with the development of cranial neuropathies after radiosurgery were scrutinized.

Methods

The authors reviewed the clinical records and radiological data in 22 consecutive patients who received GKS for a trigeminal schwannoma. The median tumor volume was 4.1 ml (0.2–12.0 ml), and the mean tumor margin dose was 13.3 ± 1.3 Gy at an isodose line of 49.9 ± 0.6% (mean ± standard deviation). The median clinical follow-up period was 46 months (range 24–89 months), and the median length of imaging follow-up was 37 months (range 24–79 months).

Results

Tumor growth control was achieved in 21 (95%) of the 22 patients. Facial pain responded best to radio-surgery, with two thirds of patients showing improvement. However, only one third of patients with facial hypesthesia improved. Six patients (27%) experienced new or worsening cranial neuropathies after GKS. Ten patients (46%) showed tumor expansion after radiosurgery, and nine of these also showed central enhancement loss. Loss of central enhancement, tumor expansion, and a tumor in a cavernous sinus were found to be significantly related to the emergence of cranial neuropathies.

Conclusions

The use of GKS to treat trigeminal schwannoma resulted in a high rate of tumor control and functional improvement. Cranial neuropathies are bothersome complications of radiosurgery, and tumor expansion in a cavernous sinus after radiosurgery appears to be the proximate cause of the complication. Loss of central enhancement could be used as a warning sign of cranial neuropathies, and for this vigilant patient monitoring is required.

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Kyung Sun Song, Sung-Hye Park, Byung-Kyu Cho, Kyu-Chang Wang, Ji Hoon Phi and Seung-Ki Kim

Meningiomas are rare in children. Chordoid meningioma is a very rare variant, as only 16 cases in children have been reported. The authors report the first case of a chordoid meningioma in the third ventricle.

A 12-year-old boy presented with headache, abnormal behaviors, and ataxia. Brain MR imaging revealed a 2-cm, well-enhanced mass in the third ventricle and hydrocephalus. Positron emission tomography with [18F]fluorodeoxyglucose showed that the mass was hypermetabolic. Gross-total removal of the mass was performed using a left frontal transcortical and transventricular approach. The mass originated from the left caudate head and was connected to the choroid plexus. A chordoid meningioma was diagnosed on the basis of the histological characteristics of the tumor, which was composed of cords and nests of eosinophilic vacuolated cells with an abundant myxoid matrix, similar to the features of a chordoma. A typical focal meningiomatous pattern was observed. The tumor cells were immunoreactive for vimentin and epithelial membrane antigen. The patient's headache and gait disturbance improved after the tumor was removed. The tumor showed no signs of recurrence during 12 months of follow-up.

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Chang Sub Lee, Ji Hoon Phi, Seung-Ki Kim, Byung-Kyu Cho and Kyu-Chang Wang

Object

Congenital dermal sinus (CDS) usually develops in the midline of the body as a single tract. To date, only a few patients with multiple CDS tracts and ostia have been reported. The authors analyzed the clinical features of patients with spinal CDS and multiple ostia and proposed a novel hypothesis for the pathogenesis of the atypical CDS.

Methods

Five patients with spinal CDS and multiple ostia were included. The clinical, radiological, and operative features of these patients were reviewed retrospectively.

Results

Three patients demonstrated bilateral paramedian ostia at the same or a very similar spinal level. One patient showed a paramedian and a midline ostium. One patient had 2 unilateral paramedian ostia at different spinal levels. The layers of the internal ending of CDS tracts were diverse. Complete removal of the tracts was possible in all patients. Two patients had dermoid tumors. All patients had an associated anomaly, such as a lumbosacral lipoma or the Currarino triad. The authors propose a “zipping error” hypothesis for the formation of dual ostia located at the spinal level of primary neurulation. An associated anomaly such as a lumbosacral lipoma may contribute to the formation of dual ostia.

Conclusions

Unilateral or bilateral dual ostia may be present in patients with CDS, especially when an associated anomaly is present. The atypical CDS may develop from aberrant neural tube closure.

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Ji Hoon Phi and Chun Kee Chung

Object

Surgical treatment of brain tumors in the mesial temporal lobe (MTL) is a highly demanding procedure. Only a few studies describing the surgery of MTL tumors have been reported, and they have been focused on the operative techniques and immediate results of the surgery. The authors have analyzed the long-term oncological outcome in patients with MTL tumors.

Methods

Thirty-six patients with an MTL tumor were studied. The mean patient age at surgery was 32 years (range 13–62 years). The tumors were confined to the MTL (Schramm Type A) in 25 patients (69%). Extension of the tumor into the fusiform gyrus (Schramm Type C) and temporal stem (Schramm Type D) was observed in 4 and 7 patients (11 and 19%), respectively. There was a significant difference in the tumor size according to Schramm types (p = 0.001). Complete tumor resection was achieved in 26 patients (72%). All tumors were low-grade lesions except for 1 anaplastic astrocytoma.

Results

After a median follow-up period of 50.5 months, 7 patients showed progression of the disease. The actuarial progression-free survival rates were 97% in the 1st year, 84% in the 2nd year, and 80% in the 5th year. The degree of tumor resection was significantly related to the tumor control failure (p < 0.001) and malignant transformation of a low-grade tumor (p < 0.001). Univariate analyses using a Cox proportional hazards model showed that the following factors were significantly associated with a failure to control the tumor: 1) extent of the tumor (Schramm Type D; p = 0.003, relative risk [RR] 12.04); 2) size of the tumor (p = 0.033, RR 1.052/mm); 3) patient age at surgery ≥ 50 years (p = 0.007, RR 8.312); and 4) short duration of epilepsy (< 6 months; p = 0.001, RR 21.54).

Conclusions

Surgery is the principal treatment for MTL tumors, despite its technical difficulty. Complete tumor resection is strongly recommended for long-term tumor control. The MTL tumors are heterogeneous in their prognosis. Older age, short duration of epilepsy, and tumor size are all associated with poor outcome. Patients with these characteristics may have a more aggressive form of the disease than those with MTL tumors associated with chronic epilepsy.

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Ji Hoon Phi and Chun Kee Chung

Object

Surgical treatment of brain tumors in the mesial temporal lobe (MTL) is a highly demanding procedure. Only a few studies describing the surgery of MTL tumors have been reported, and they have been focused on the operative techniques and immediate results of the surgery. The authors have analyzed the long-term oncological outcome in patients with MTL tumors.

Methods

Thirty-six patients with an MTL tumor were studied. The mean patient age at surgery was 32 years (range 13–62 years). The tumors were confined to the MTL (Schramm Type A) in 25 patients (69%). Extension of the tumor into the fusiform gyrus (Schramm Type C) and temporal stem (Schramm Type D) was observed in 4 and 7 patients (11 and 19%), respectively. There was a significant difference in the tumor size according to Schramm types (p = 0.001). Complete tumor resection was achieved in 26 patients (72%). All tumors were low-grade lesions except for 1 anaplastic astrocytoma.

Results

After a median follow-up period of 50.5 months, 7 patients showed progression of the disease. The actuarial progression-free survival rates were 97% in the 1st year, 84% in the 2nd year, and 80% in the 5th year. The degree of tumor resection was significantly related to the tumor control failure (p < 0.001) and malignant transformation of a low-grade tumor (p < 0.001). Univariate analyses using a Cox proportional hazards model showed that the following factors were significantly associated with a failure to control the tumor: 1) extent of the tumor (Schramm Type D; p = 0.003, relative risk [RR] 12.04); 2) size of the tumor (p = 0.033, RR 1.052/mm); 3) patient age at surgery ≥ 50 years (p = 0.007, RR 8.312); and 4) short duration of epilepsy (< 6 months; p = 0.001, RR 21.54).

Conclusions

Surgery is the principal treatment for MTL tumors, despite its technical difficulty. Complete tumor resection is strongly recommended for long-term tumor control. The MTL tumors are heterogeneous in their prognosis. Older age, short duration of epilepsy, and tumor size are all associated with poor outcome. Patients with these characteristics may have a more aggressive form of the disease than those with MTL tumors associated with chronic epilepsy.

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Eun Jung Koh, Ji Hoon Phi, Sung-Hye Park, In-One Kim, Jung-Eun Cheon, Kyu-Chang Wang, Byung-Kyu Cho and Seung-Ki Kim

This 14-year-old boy presented with left hemiparesis, gait disturbance, and multiple cranial nerve palsies. Magnetic resonance imaging revealed a multicystic mass with hemorrhagic fluid–fluid levels in the right midbrain, suggesting the presence of a cavernous malformation. Diffusion tensor imaging showed the mass to be close to the right corticospinal tract and ipsilateral medial lemniscus. Subtotal removal of the mass was performed via a right subtemporal approach. The histopathological diagnosis was of a mixed germ cell tumor (GCT) comprising mature teratoma and germinoma cells with syncytiotrophoblastic giant cells. The patient underwent postoperative chemotherapy and radiotherapy, and no tumor progression was found during 1 year of follow-up.

Intracranial GCTs arise mainly in the pineal and the suprasellar area. Germ cell tumors in the brainstem are rare, with only 12 reported cases. Among these, 4 were in the midbrain and histologically were pure germinomas. To the authors' knowledge, this is the first reported case of a mixed GCT in the midbrain combining mature teratoma and germinoma cells.

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Seong-Cheol Park, Seung-Ki Kim, Byung-Kyu Cho, Hyun Jib Kim, Jeong Eun Kim, Ji Hoon Phi, In-One Kim and Kyu-Chang Wang

Object

Sinus pericranii (SP) is a rare venous varix in an extracranial location connected to the intracranial venous system. The aim of this retrospective study was to report on 16 pediatric cases of SP with consideration of the preoperative evaluation of surgical risk.

Methods

The study population consisted of 10 patients who had undergone surgery for SP and 6 patients with concomitant craniosynostosis and SP. The mean age of the patients at presentation was 3.7 years. To identify characteristics of SP with high operative risk, 8 cases in this report and 11 previously reported cases of SP with sufficient information were categorized on the basis of the number and size of SP, the number and size of transcranial channels, the venous drainage type, and the amount of blood loss. Hemorrhage amounts were classified into 3 grades based on the description of intraoperative blood loss.

Results

Sinus pericranii not associated with craniosynostosis were resected without any postoperative morbidity. Sinus pericranii associated with craniosynostosis were preserved. After craniofacial reconstruction, 2 cases of SP with craniosynostosis regressed, completely in one patient and partially in another. These 2 patients with SP were confirmed to have compromised intracranial sinus before craniofacial reconstruction. Among a total of 19 patients, multiplicity or size (> 6 cm) of SP (p = 0.036) and multiplicity (> 3) or size (> 3 mm) of transcranial channels (p = 0.004) was associated with more severe hemorrhage grade. Sinus pericranii with peripheral venous drainage (drainer type) was not associated with hemorrhage grade after classification into 3 grades (p = 0.192). However, all 3 cases of SP with massive Grade 3 hemorrhage were the drainer type. Hemorrhage grade was correlated with the number of risk factors for SP (r = 0.793, p < 0.001).

Conclusions

Three risk factors of SP and the presence of compromised intracranial sinus are markers for highrisk SP. “Squeezed-out sinus syndrome” is suggested as a concept for SP associated with compromised intracranial sinus, mainly caused by craniosynostosis. Sinus pericranii in squeezed-out sinus syndrome probably serves as a crucial alternative to venous drainage of the brain with intracranial venous compromise. Conservative treatment for such patients with SP is recommended.

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Ji Yeoun Lee, Bo Sung Kim, Ji Hoon Phi, Hyoung Jin Kang, Sung-Hye Park, Kyu-Chang Wang, Il Han Kim, Byung-Kyu Cho and Seung-Ki Kim

Primary sarcomas of the CNS are rare and are sometimes associated with chronic subdural effusion (SDE). Approximately 10 patients with such presentations have been reported. The authors report the case of a 5-year-old boy with multiple subdural masses and SDE. An SDE had been diagnosed when the patient was 2 months old, and he received a subduroperitoneal shunt when he was 5 months old. Since then, he had been clinically stable and well for 5 years. When he presented with acute headache, nausea, and vomiting, a newly developed tumor was found. Near-total resection of the tumor was performed, and the mass was diagnosed as an embryonal-type rhabdomyosarcoma. The child was given radiation therapy and 13 cycles of chemotherapy and is still free of disease 13 months after surgery.