Biomedical subjects

Sun Ha Paek

Publications and source records attributed to Sun Ha Paek.

At least 19 recordsLinked to original sources

PubMed2006

Therapeutic strategy for large vestibular schwannomas.

Management of large vestibular schwannoma (VS) remains a difficult problem for which the extent of tumor resection and the role of radiosurgery continue to be the subject of debate. To develop an optimal therapeutic strategy for large VS, various treatment options within the avenues of microsurgery and radiosurgery were evaluated and compared. The authors carefully reviewed the clinical data of 50 surgical cases of large VS, defined as tumors with an average diameter over 3 cm in magnetic resonance imaging (MRI). All patients underwent microsurgery as the primary treatment. Gross total removal (GTR) was achieved in nine patients (18%), near total removal (NTR) in 8 (16%), radical subtotal removal (R-STR) in 31 (62%), and subtotal removal (STR) in 2 (4%). Among the 33 patients with R-STR and STR, eight had undergone adjuvant radiosurgery for the residual mass. Average tumor volume and diameter were 26.8 cm(3) (13.5-55.1) and 36.4 mm (30.0-47.2), respectively. The mean follow-up duration was 113 months (58-167). The tumor control rate and facial nerve function according to the extent of removal were analyzed. The overall tumor control rate was 82%. Perfect tumor control was achieved after NTR and R-STR with adjuvant radiosurgery. However, 11% (1 of 9) of GTR patients and 32% (8 of 25) of R-STR-only and STR patients showed recurrence or regrowth. Overall favorable outcome of facial nerve function (H-B grade 1 or 2) was achieved in 78% of the patients. The facial nerve preservation rate was inversely proportional to the extent of tumor removal. NTR or R-STR with adjuvant radiosurgery might be acceptable therapeutic options for large VS in terms of achieving good tumor control and functional preservation of facial nerve.

Facial Nerve Injuries↗

PubMed2006

The selection of the optimal therapeutic strategy for petroclival meningiomas.

BACKGROUND: Broad experience with the management of petroclival meningiomas was analyzed to optimize therapeutic strategy. METHODS: The records of 75 patients with petroclival meningioma were reviewed. The population was divided into a microsurgery group (n = 49), a radiosurgery group (n = 12), a radiation therapy group (n = 5), and an observation group (n = 9) according to the modality of primary treatment. In the microsurgery group, the tumor was completely resected in 10 patients. Eleven of the 39 patients with incomplete resections sequentially underwent adjuvant radiation therapy or radiosurgery. The median follow-up period was 86 months (range, 48-210 months). The median follow-up period of the radiosurgery, the radiation therapy, and the observation group was 52 months (range, 48-71 months), 56 months (range, 51-72 months), and 63 months (range, 53-68 months), respectively. Management outcomes were evaluated with respect to tumor control rate, neurological deficit, and functional status assessed by the Karnofsky Performance Score. RESULTS: In the microsurgery group, 11 (22.4%) patients eventually showed tumor progression. However, there was only one recurrence if adjuvant therapy was used after incomplete removal. The incidence of favorable outcomes for cranial neuropathies was better in the incomplete resection group (69.2%) than for patients in the complete resection group (20%, P = .032). Moreover, a favorable functional outcome predominated in the incomplete resection group (76.9%) compared with the complete resection group (30%, P = .049). The disease was stable in both the radiation therapy and the radiosurgery groups during the follow-up period, with functional status and cranial nerve function perfectly preserved in these patients. No predictive factor other than short symptom duration was found to be significant. CONCLUSIONS: Because the growth rate of petroclival meningioma is low and good functional status can be guaranteed, intended incomplete resection should be considered as an acceptable treatment option. Adjuvant treatment after surgery is useful in the control of residual tumors. Radiosurgery may be appropriate as the primary treatment in asymptomatic patients with small tumor; however, more aggressive treatment is needed in young patients or patients with short symptom durations.

Adolescent↗

PubMed2006

Surgically treated tuberculum sellae and diaphragm sellae meningiomas: the importance of short-term visual outcome.

OBJECTIVE: The visual outcome in patients with tuberculum and diaphragm sellae meningiomas treated with microsurgery was evaluated. Prognostic and diagnostic values of short- and long-term postoperative visual outcome and etiology for postoperative visual deterioration are discussed with special attention. METHODS: Clinical data for 30 surgically treated patients with tuberculum and diaphragm sellae meningiomas were reviewed retrospectively. The mean duration of the follow-up period was 75.9 months (range, 12-151 mo). Mean tumor diameter and volume was 25.9 mm (range, 16.3-63.3 mm) and 12.4 cm (range, 2.3-125.6 cm). A visual impairment score was used to assess the short-term (< or =2 wk after surgery) and the long-term (>6 mo after surgery) postoperative visual outcome. Various predictive factors for visual outcome were tested statistically. RESULTS: Complete resection was achieved in 23 out of 30 (76.7%) patients. Average preoperative, short- and long-term visual impairment scores were 48.2, 43.4, and 40.9, respectively. Favorable visual outcome was achieved in 80% of patients in the short term and 70% in the long term. Short-term postoperative aggravation of visual function was an ominous sign of further aggravation or at least of little hope for recovery, whereas there was a tendency to improve in the long term if short-term postoperative visual function showed favorable outcome. Recurrence or regrowth of tumor fully was responsible for late deterioration of visual function. No significant prognostic factor for visual outcome could be found. CONCLUSION: Short-term postoperative visual outcome was a strong indicator of permanent visual outcome after surgery for tuberculum sellae and diaphragm sellae meningiomas.

Adult↗

PubMed2006

Bo Sung Sim (1924-2001): a pioneer of neurosurgery in Korea.

Bo Sung Sim (1924-2001) stands as a prominent figure in the history of Korean neurosurgery. His devoted contributions have led to the fruitful development of modern neurosurgery in Korea. Sim practiced advanced neurosurgical techniques, undertook basic research, was passionate about education in the early years of neurosurgery in Korea, and played an essential role in founding the Korean Neurosurgical Society. Sim was a true neurosurgeon-a teacher, a scientist, and a superb pioneer in Korean neurosurgery.

Education, Medical↗

PubMed2006

Microhemorrhage, a possible mechanism for cyst formation in vestibular schwannomas.

OBJECT: Cystic vestibular schwannoma (VS) is a unique subgroup of VSs characterized by unpredictable expansion of the cyst component. Little is known, however, about the mechanism of cyst formation. In this study the authors compared neuroimaging and histological characteristics of cystic with solid VS to determine the pathogenesis of the cystic subgroup. METHODS: Two cohorts, one comprising 10 patients with cystic VS and the other comprising 10 patients with solid VS, were studied. Surgery was chosen as the primary treatment in all patients, with no other modality applied. Preoperative magnetic resonance images and histological characteristics of the tumor in patients with cystic VSs were evaluated and compared with those in the group with solid VSs. Differences between the two groups were assessed using the chi-square test. Neuroimaging findings revealed that either fluid-fluid level or hemosiderin deposit was present in all cystic VSs. Histological evidence of microhemorrhage, such as hemosiderin-laden macrophages (p = 0.069), hemosiderin deposits (p = 0.019), thrombotic vessels (p = 0.008), and abnormal vessel proliferation (p = 0.006) were more prominent in cystic VSs compared with solid ones. There was no difference in Antoni type dominance and Ki-67 proliferative index between the two groups. CONCLUSIONS: Intratumoral microhemorrhage is a possible mechanism of pathogenesis in cystic VS.

Adult↗

PubMed2006

Recurrent juvenile nasopharyngeal angiofibroma treated with gamma knife surgery.

Radiosurgery has been rarely applied for juvenile nasopharyngeal angiofibroma (JNA) and cumulative reports are lacking. The authors report a case of successful treatment of recurred JNA with gamma knife surgery (GKS). A 48-yr-old man was presented with right visual acuity deterioration and brain magnetic resonance images (MRI) disclosed a 3 cm-sized intraorbital mass in the right orbit. He underwent a right fronto-temporal craniotomy and the mass was subtotally removed to preserve visual function. Histological diagnosis confirmed JNA in typical nature. However, the vision gradually worsened to fail four years after operation. MRI then showed regrowth of the tumor occupying most of the right orbit. GKS was done for the re-curred lesion. A dose of 17 Gy was delivered to the 50% isodose line of tumor mar-gin. During the following four-year follow-up period, the mass disappeared almost completely without any complications. Usually JNA can be exclusively diagnosed by radiological study alone. So this report of successful treatment of JNA with GKS may provide an important clue for the novel indication of GKS.

Adolescent↗

PubMed2006

The role of matrix metalloproteinases and tissue inhibitors of matrix metalloproteinase in microcystic meningiomas.

We studied the expression of matrix metalloproteinases (MMP) and tissue inhibitors of matrix metalloproteinase (TIMP) in microcystic meningiomas to investigate a possible underlying mechanism for the development of microcysts and of peritumoral edema, which are frequent characteristics of this rare subtype. Between October 1995 and June 2004, 10 of 19 patients who had histologically confirmed pure microcystic meningiomas were enrolled in the study. Six patients with meningothelial meningiomas, three with atypical meningiomas, and one with a transitional meningioma were included as a control group. Immunohistochemistry with paraffin blocks and real-time RT-PCR analysis for MMP-2, MMP-9, TIMP-1, TIMP-2 and vascular endothelial growth factor (VEGF) were performed using stored frozen tissues. Compared with the control group, MMP-9 was invariably and highly expressed in immunohistochemical staining of microcystic meningiomas. MMP-2, TIMP-1, TIMP-2 and VEGF were weakly expressed or not expressed in both microcystic and non-microcystic meningiomas. Real-time RT-PCR showed increased ratios of MMP-9 to TIMP-1 in microcystic meningiomas compared with the control group (55.855 +/- 106.353 vs. 1.858 +/- 2.575, respectively; p = 0.00). The expression of MMP-2 (0.72 +/- 1.20 vs. 2.54 +/- 3.01, p = 0.01) and TIMP-2 (1.22 +/- 1.67 vs. 1.61 +/- 1.82, p = 0.02) was higher in the control group. The results suggested that the increased ratio of MMP-9 to TIMP-1 might be associated with the formation of microcysts and peritumoral edema in microcystic meningioma.

Adult↗

PubMed2005

Hearing preservation after gamma knife stereotactic radiosurgery of vestibular schwannoma.

BACKGROUND: To evaluate the hearing preservation rate and to determine its prognostic factors after gamma knife (GK) stereotactic radiosurgery (SRS) in patients with vestibular schwannoma, the authors used a prospective study design to analyze these patients. METHODS: Between December 1997 and January 2002, 25 patients with vestibular schwannoma with serviceable hearing were enrolled in the current study. The median tumor volume was 3.0 cc (0.16-9.1 cc). The prescription dose was 12.0 +/- 0.7 gray at an isodose line of 49.8 +/- 1.1%. The tumor control rate and complications were evaluated by focusing on hearing preservation and its prognostic factors. RESULTS: Based on radiologic study, the tumor control rate was 92% during the median follow-up period of 45 months. The trigeminal and facial nerve preservation rates were 95% and 100%, respectively. Thirteen (52%) of the 25 patients preserved serviceable hearing and 9 (36%) patients retained their pre-GK G-R grade levels after GK SRS. However, 16 patients showed hearing deterioration > 20 dB within 3-6 months and this trend continued for 24 months after the treatment. The maximum radiotherapy dose delivered to the cochlear nucleus was the single, significant prognostic factor of hearing deterioration. CONCLUSIONS: The authors concluded that a more sophisticated strategy to prevent hearing deterioration during the first 6 months post-GK SRS is necessary to improve long-term hearing preservation.

Adult↗

PubMed2005

Patient-specific embryonic stem cells derived from human SCNT blastocysts.

Patient-specific, immune-matched human embryonic stem cells (hESCs) are anticipated to be of great biomedical importance for studies of disease and development and to advance clinical deliberations regarding stem cell transplantation. Eleven hESC lines were established by somatic cell nuclear transfer (SCNT) of skin cells from patients with disease or injury into donated oocytes. These lines, nuclear transfer (NT)-hESCs, grown on human feeders from the same NT donor or from genetically unrelated individuals, were established at high rates, regardless of NT donor sex or age. NT-hESCs were pluripotent, chromosomally normal, and matched the NT patient's DNA. The major histocompatibility complex identity of each NT-hESC when compared to the patient's own showed immunological compatibility, which is important for eventual transplantation. With the generation of these NT-hESCs, evaluations of genetic and epigenetic stability can be made. Additional work remains to be done regarding the development of reliable directed differentiation and the elimination of remaining animal components. Before clinical use of these cells can occur, preclinical evidence is required to prove that transplantation of differentiated NT-hESCs can be safe, effective, and tolerated.

Adult↗

PubMed2005

Integration of surgery with fractionated stereotactic radiotherapy for treatment of nonfunctioning pituitary macroadenomas.

OBJECTIVE: To evaluate the efficacy of fractionated stereotactic radiotherapy (FSRT) after surgery in the management of residual or recurrent nonfunctioning pituitary adenomas with respect to tumor control and the development of complications. METHODS AND MATERIALS: The clinical records of patients with nonfunctioning pituitary adenomas who underwent FSRT were retrospectively analyzed. For newly diagnosed tumors, transsphenoidal surgery was performed, and, if residual tumor was identified at 3 months, FSRT was performed. If significant tumor volume persisted, transcranial surgery was performed before FSRT. We originally initiated FSRT with 2-Gy fractions to 46 Gy. We escalated the dose to 50.4 Gy thereafter. As a final modification, we dropped the daily dose to 1.8-Gy fractions delivered within 6 weeks. High-dose conformality and homogeneity was achieved with arc beam shaping and differential beam weighting. The radiographic, endocrinologic, and visual outcomes after FSRT were evaluated. RESULTS: The 68 patients included 36 males and 32 females with an age range of 15-81 years. The median follow-up was 30 months (range, 2-82 months), and the median tumor volume was 6.2 cm(3). Of the 68 patients, 20 were treated to 46 Gy and 48 to 50-52.2 Gy. Most were treated to 50.4 Gy. Eleven patients had recurrent tumors, 54 had residual tumors, and no surgery was performed in 3 patients before FSRT. We noted no radiation-induced acute or late toxicities, except for radiation-induced optic neuropathy in 2 patients. At latest follow-up, the tumor had decreased in size in 26 patients and remained stable in 41 of the 42 remaining patients. Of the 68 patients, 4 (6%) developed hypopituitarism at 6, 11, 12, and 17 months after FSRT. Reviewing available serial Humphrey visual fields, visual fields were objectively improved in 28 patients, and remained stable in 24 patients, and worsened in 2 patients. CONCLUSION: The findings of this analysis support the use of surgery followed by FSRT as a safe, effective, and integrated treatment for nonfunctioning pituitary adenomas. Additional follow-up is needed to document the long-term tumor control rates, preservation rates for vision and pituitary function, and neurocognitive outcomes.

Adenoma↗

PubMed2005

Immunohistochemical study of central neurocytoma, subependymoma, and subependymal giant cell astrocytoma.

For investigation of histogenesis of central neurocytomas (CNs), subependymoma (SEs), subependymal giant cell astrocytomas (SEGAs), we studied expression of various neuronal and glial biomarkers by immunohistochemical (IHC) study and reverse transcriptase-polymerase chain reaction (RT-PCR). The materials for IHC were paraffin section of seven CNs, three SEs, and eight SEGAs and those for RT-PCR were frozen tissues of seven CNs, three SEs, and five SEGAs. Control group was five ependymomas (EPs) and four pilocytic astrocytomas (PAs). The neuronal biomarkers included nestin, chromogranin A (chrA), synaptophysin (SNP), neuronal cell adhesion molecule (NCAM), neuron specific enolase (NSE), neuronal nuclear antigen (NeuN), neurofilament (NF) and the glial marker was GFAP. CNs expressed all neuronal markers except NF (0%), SNP (100%), NCAM (100%), NSE (100%), NeuN (100%), nestin (29%) and chrA (43%), but GFAP expression was found only in one case (14%). SEGA coexpressed several neuronal markers and a glial marker; NeuN (100%), NSE (88%), NCAM (63%), nestin (100%), SNP (weakly and focally, 100%), and GFAP (100%), however, other neuronal markers including chrA, SNP and NF were all negative. SE expressed nonspecific neuronal markers (NCAM (100%) and NSE (100%)) which showed weak intensity and a GFAP (100%), but not nestin. Among control cases of EPs and PAs, no one case expressed neuronal markers except nonspecific neuronal marker of NCAM, but robustly expressed GFAP. RT-PCR product of nestin was expressed in 29% of CNs (2/7cases), 60% of SEGAs (3/5 cases), 100% of SEs (3/3 cases), 80% of EPs (4/5 cases), and 25% of PAs (1/4 cases). Conclusively, coexpression of neuronal and glial markers and expression of nestin in CNs, SEGAs and SEs suggested the origin of these tumor cells might be the stem cells being able to differentiate into both neuronal and glial phenotypes. But CNs might be originated from rather neuronally committed stem cells and SEs from rather glially committed stem cells.

Astrocytoma↗

PubMed2005

Aggressive vestibular schwannomas showing postoperative rapid growth - their association with decreased p27 expression.

Vestibular schwannomas (VSs) are relatively slow growing tumors. However, some rapidly regrow or recur after surgical resection. The objective of this study was to identify those molecular characteristics predicting rapid recurrence after surgical resection. Immunohistochemically determined expressions of several cell cycle regulators and apoptosis-associated proteins in 12 cases of aggressive VS (AVS) and in 15 control cases of usual VS (UVS) cases were compared. The expressions of p53 and Bax (pro-apoptotic protein), Bcl-2 (anti-apoptotic protein), Fas, and Fas-L (apoptotic death receptor and ligand), caspase 3 (apoptotic effector caspase proteins), and p27 and p21 (cyclin-dependent kinase inhibitors) were analyzed using tissue array blocks. Loss of p27 expression was observed in 8 of 12 AVS cases (67%) and in 3 UVS cases (20%); p21 was expressed in all cases. Loss of Bax was observed in 3 AVS and 3 UVS cases. The anti-apoptotic protein, Bcl-2, was expressed in 9 AVS (75%) and 11 UVS (73%), and p53, Fas-L, and caspase 3 were negative and Fas was positive in all AVS and UVS cases. Of these, only the loss of p27 was statistically significant (P = 0.02). The loss of p27 in AVS may explain the unusually high proliferative potential of AVS versus UVS, and p27 may be a predictor of VS aggressiveness. The expressions of other apoptosis associated proteins were not significantly different in the two groups. This may be the first report to identify a molecular entity associated with aggressive VS. However, further studies are required.

Cell Proliferation↗

PubMed2005

Gamma knife surgery of superficially located meningioma.

OBJECT: The authors analyzed tumor control rates and complications in patients with superficially located meningiomas after gamma knife surgery (GKS). METHODS: Between 1998 and 2003, GKS was performed in 23 patients with 26 lesions in whom follow-up imaging for 1 year or more was available. The male/female ratio was 1:22. The mean age was 59 years. The median tumor volume was 4.7 cm3, and the mean margin dose was 16 Gy at the 50% isodose line. Peritumoral edema was revealed on magnetic resonance (MR) imaging in four patients before GKS. Magnetic resonance imaging and clinical examinations were performed every 6 months after GKS. The mean follow-up duration was 32 months. The tumor shrank in eight cases, was stable in 17, and enlarged in one; thus 25 (95%) of 26 tumors were controlled. A peritumoral high signal on T2-weighted MR images was found in eight lesions and preexisting edema was aggravated in three lesions after GKS. Ten of these 11 patients complained of severe headache, and three patients experienced neurological deficits at the same time after a mean latency of 3 months; however, high signal was not demonstrated on imaging before 6 months on average. Steroid agents, when required, gave relief to all patients. The complication rate was 43% (10 of 23 cases). High signal disappeared in nine patients and decreased in the remaining two. High signal was associated with a high integral dose and a large tumor volume. Tumor shrinkage at the last follow-up examination was more prominent in the patients with symptomatic high signal (p = 0.03). CONCLUSIONS: There was a good tumor control rate with a high complication rate. Longer follow up of more patients is needed. Adjusting the dose-volume relationship should be considered to reduce complications.

Adult↗

PubMed2005

Reevaluation of surgery for the treatment of brain metastases: review of 208 patients with single or multiple brain metastases treated at one institution with modern neurosurgical techniques.

OBJECTIVE: Patients with brain metastases were analyzed retrospectively to assess the risks and benefits of surgery with modern neurosurgical techniques, including image guidance coupled as indicated with corticography. METHODS: We retrospectively analyzed charts of patients treated surgically for brain metastases. We identified patients with single or multiple brain metastases who underwent craniotomies to reverse associated neurological symptoms or establish a diagnosis. We assessed patients according to recursive partitioning analysis (RPA) prognostic groups as well as functional grades of tumor location (eloquent versus noneloquent, Grades I-III). Perioperative complications, neurological outcomes after surgery, survival, and prognostic factors were analyzed. Statistical analysis of survival was performed with the Kaplan-Meier method. A P value of <0.05 was considered statistically significant. RESULTS: Two hundred eight patients were treated between March 1995 and December 2002. Patient age ranged from 31 to 82 years (median, 59 yr). One lesion was resected in 191 patients, and of 76 patients with multiple lesions, two or more metastases were resected in 17 patients. Tumors were located in eloquent cortex in 27 patients and near eloquent cortex in 124 patients. Four patients died within 30 days after surgery for a mortality rate of 1.9%. Neurological deterioration was noted in 13 patients (6%) after surgery for Grade I and II tumors and in 5 patients (19%) of 27 patients with Grade III tumors. Karnofsky Performance Scale scores were improved (68 patients) or unchanged (124 patients) in 192 patients and worse in 16 patients after surgery. The median survival time (MST) from the date of surgery was 8 months for all patients and 9 months for 163 patients who did not undergo prior whole-brain radiation therapy. There was no difference in survival between patients operated for single metastasis (MST, 8 mo) versus patients with two or three metastases (MST, 9 mo; P = 0.9364). By both univariate and multivariate analysis, variables significantly affecting outcome included a high Karnofsky Performance Scale score and RPA Class I assignment. By univariate analysis, significant treatment variables included postoperative radiotherapy and postoperative chemotherapy. The MSTs of RPA Class I, II, and III patients were 16.1 months, 7.2 months, and 1.4 months, respectively (P < 0.001, log-rank test). These survival data compare favorably with the stereotactic radiosurgery boost arm of the recently published Radiation Therapy Oncology Group 9508 trial. CONCLUSION: In most patients with single or multiple brain metastases, surgical resection reversed or stabilized neurological symptoms with therapeutic benefit, conveying a notable survival advantage without apparent increased risk, particularly in RPA Class I patients. In patients with Grade III single metastasis or RPA Class II multiple metastasis, surgical judgment should be exercised, and stereotactic radiosurgery boost treatment may be preferable. An algorithm for treatment of brain metastases is proposed.

Adult↗

PubMed2004

Forskolin promotes astroglial differentiation of human central neurocytoma cells.

Human central neurocytoma is a kind of the brain tumors that are usually found in anterior part of the lateral ventricles. In this study, we established conditions that allowed proliferation of neurocytoma cells culture and analyzed characteristics of neurocytoma cells in vitro. For in vitro, a condition that used for culturing neural stem cells and contained basic fibroblast growth factor (bFGF) provided high proliferation. RT-PCR analaysis showed that nestin was found in neurocytoma cells, indicating that the neurocytomas possess neural stem cell properties. Interestingly, treatment of neurocytoma cells with forskolin increased expression of glial fibrillary acidic protein with a concomitant decrease in the nestin expression. Forskolin also induced morphological changes of neurocytoma cells to adopt an astrocyte-like phenotype. The results suggest that neurocyotma cells may have properties of multipotent neural stem cells.

Animals↗

PubMed2004

Surgical treatment of symptomatic Rathke cleft cysts: clinical features and results with special attention to recurrence.

OBJECT: Rathke cleft cysts (RCCs) are rarely symptomatic. The purpose of this study was to clarify the clinical, neuroimaging, surgical, and pathological features of symptomatic RCCs with special attention to their recurrence. METHODS: This retrospective study involved 53 patients with pathologically confirmed symptomatic RCCs. There were 28 female and 25 male patients, ranging in age from 11 to 68 years (mean 37 years). Common clinical presentations included headache, visual impairment, and endocrine disturbance. The most common endocrine disturbances were hyperprolactinemia and diabetes insipidus. Most of these improved or were resolved after surgery, with the exception of diabetes insipidus and panhypopituitarism. The cysts were intrasellar with suprasellar extension in 33 patients, and ranged in size from 5 to 40 mm (mean 17 mm). In the 50 magnetic resonance (MR) images that were reviewed, the signal intensities were quite variable. Fourteen MR images demonstrated enhancement after an injection of Gd. Intraoperatively, the cyst contents were found to be yellowish (18 patients [37%]) and mucoid (25 patients [51%]). Pathological examinations revealed a pseudostratified columnar epithelium in 26 patients (49%). Abundant squamous metaplasia and a stratified squamous epithelium were also found in 12 patients (23%). Follow-up MR images revealed cyst recurrences that required a repeated operation in six patients. Statistically significant risk factors for a recurrence included enhancement of the lesion on MR images (p = 0.017), the extent of cyst removal (p = 0.012), and the presence of squamous epithelium (p = 0.008). CONCLUSIONS: Rathke cleft cysts are associated with a variety of clinical presentations and sometimes confusing intraoperative and pathological findings. Close postoperative observation with neuroimaging and neuroophthalmological assessment is necessary, especially after a partial removal, as in cases with squamous metaplasia.

Adolescent↗

PubMed2003

Steroidogenic acute regulatory protein expression in the normal human brain and intracranial tumors.

In this study we found the expression of steroidogenic acute regulatory protein (StAR) mRNA and protein in both the normal human brain and intracranial tumors, using RT-PCR and immunohistochemistry. StAR mRNA is expressed at a very low level in the white matter of the normal human brain, but in tumoral tissues StAR mRNA was specifically expressed in oligodendrogliomas and malignant glial tumors. StAR-positive cells were also detected in the normal human brains and gliomas; its frequency and density were higher in glioma tissue. These findings suggest that StAR expression might be correlated with the growth of glial tumors.

Brain↗

PubMed2003

Meningeal hemangiopericytomas: long-term outcome and biological behavior.

BACKGROUND: The authors present a retrospective clinical analysis of meningeal hemangiopericytomas. The long-term outcome and biologic behavior, including local recurrence and extraneural distant metastasis, are elucidated. METHOD: Clinical records and radiologic findings of 31 cases with meningeal hemangiopericytoma treated at Seoul National University Hospital and Asian Medical Center between 1982 and 1999 were carefully reviewed. The final outcome was determined by direct or phone contact and questionnaire by mail. The duration of follow-up was from 1 to 216 months (mean 77). All patients underwent craniotomy and Simpson Grade I or II resection was possible in 24 patients. Conventional radiotherapy was given in 11 patients (in 5 after total excision and in 6 for residual mass) and stereotactic radiosurgery was conducted in 6 cases. RESULTS: Intracranial recurrence was seen in 12 cases (38.7%) and the mean period before the first recurrence was 104 months. The recurrence was at the primary site in 11 cases and diffuse leptomeningeal seeding occurred in the remaining case. The 5-year recurrence free rate was 59.2% and the extent of excision was the significant factor (72.7% in total excision group and 20.8% in the incomplete excision group, p = 0.006). In four patients (12.9%), extraneural metastases developed at an average of 107 months. Six patients died during the follow-up period; however, 2 of these died of unrelated causes. CONCLUSIONS: Complete excision is the most important factor in reducing recurrence. However, recurrence may occur even after complete excision. Careful long-term follow-up is mandatory because of the long disease-free interval.

Adult↗