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Peter C Burger

Publications and source records attributed to Peter C Burger.

At least 37 records · Page 2Linked to original sources
PubMed2005

Neurocytoma of the VIIIth cranial nerve: case report.

OBJECTIVE AND IMPORTANCE: Neurocytomas are uncommon tumors of the CNS. To date, none have been described in association with a cranial nerve. We described the clinicopathological features of an example arising in the cochlear-vestibular portion of the VIIIth nerve with extension into the cerebellopontine angle. CLINICAL PRESENTATION: The patient, a 42-year-old female, presented approximately 6 months ago with several episodes of worsening dizziness. On magnetic resonance imaging studies, a 2-cm enhancing lesion occupying the left internal auditory canal and protruding into the cerebellopontine angle cistern was detected with signal characteristics suggestive of vestibular neuroma. INTERVENTION: At surgery, the tumor was seen to originate from the cochlear-vestibular nerve bundle lying within the internal auditory canal, extended laterally to the level of the fundus and 4 mm medially into the cerebellopontine angle. No dural attachment was noted. With use of sharp dissection and bipolar cautery, portions of the tumor within the auditory canal were debulked. CONCLUSION: A unique example of a neurocytoma in association with a cranial nerve is documented. Possible explanations for the occurrence are explored. The topography of neurocytomas continues to expand.

Adult↗
PubMed2004

Pilomyxoid astrocytoma: a review.

Pilomyxoid astrocytoma (PMA) is a recently described type of brain tumor. PMA shares similar features with pilocytic astrocytoma (PA), the most common central nervous system (CNS) tumor in the pediatric population, yet displays subtle histologic differences. Previous studies have shown PMA to behave more aggressively than PA, with shorter progression-free and overall survival as well as a higher rate of recurrence and CNS dissemination. These findings suggest that PMA may be a unique and distinct neoplasm. This review summarizes the histologic, clinical, and radiographic characteristics of PMA. In addition, the current treatment options and research endeavors involving this disease are described. Increased recognition of PMA within the medical community has the potential to affect the treatment and prognosis of pediatric low-grade astrocytomas.

Astrocytoma↗
PubMed2004

Small cell astrocytoma: an aggressive variant that is clinicopathologically and genetically distinct from anaplastic oligodendroglioma.

BACKGROUND: Small cell glioblastoma (GBM) is a variant with monomorphous, deceptively bland nuclei that often is misdiagnosed as anaplastic oligodendroglioma. METHODS: To elucidate its clinicopathologic and genetic features, the authors studied 71 adult patients (median age, 57 years), including 22 patients who were identified from a set of 229 GBMs (10%) that had been characterized previously by epidermal growth factor receptor (EGFR)/EGFR-vIII variant immunohistochemistry. Tumors also were analyzed by fluorescence in situ hybridization for 1p, 19q, 10q, and EGFR copy numbers. RESULTS: Radiologically, 37% of tumors that were not selected for grade showed minimal to no enhancement. Similarly, 33% of tumors had no endothelial hyperplasia or necrosis histologically, qualifying only as anaplastic astrocytoma (Grade III) using World Health Organization criteria. Nevertheless, such tumors progressed rapidly, with mortality rates that were indistinguishable from their Grade IV counterparts. The median survival for 37 patients who were followed until death was 11 months. Oligodendroglioma-like histology included chicken-wire vasculature (86%), haloes (73%), perineuronal satellitosis (58%), and microcalcifications (45%), although mucin-filled microcystic spaces were lacking. No small cell astrocytomas had 1p/19q codeletions, whereas EGFR amplification and 10q deletions were present in 69% and 97% of small cell astrocytomas, respectively. The tumors expressed EGFR and EGFR-vIII more commonly than nonsmall cell GBMs (83% vs. 35% [P < 0.001]; 50% vs. 21% [P < 0.001] respectively). CONCLUSIONS: Small cell astrocytoma is an aggressive histologic variant that behaved like primary GBM, even in the absence of endothelial hyperplasia and necrosis. Despite considerable morphologic overlap with anaplastic oligodendroglioma, clinicopathologic and genetic features were distinct. Fifty percent of small cell astrocytomas expressed the constitutively activated vIII mutant form of EGFR, and molecular testing for 10q deletion improved the diagnostic sensitivity over EGFR alone.

Adult↗
PubMed2004

Proton magnetic resonance spectroscopic imaging in pediatric pilomyxoid astrocytoma.

OBJECTS: A pilomyxoid astrocytoma (PmA) is considered to be either a more aggressive variant of a pediatric pilocytic astrocytoma (PA) or a tumor of a separate entity. METHODS: We present two cases of pediatric optic-chiasmatic PmA. Proton magnetic resonance spectroscopic imaging (MRSI) of the PmA revealed decreased concentrations of total choline (Cho), creatine (Cr), and N-acetyl aspartate (NAA). In contrast, proton MR spectra of PAs showed elevated Cho and decreased Cr and NAA signals. CONCLUSION: Low metabolite concentrations in PmAs detected by MRSI may therefore help to distinguish PmAs from PAs preoperatively.

Aspartic Acid↗
PubMed2004

Gliosarcoma: cytopathologic characteristics on fine-needle aspiration (FNA) and intraoperative touch imprint.

Gliosarcoma (GS) is a rare subtype of glioblastoma multiforme (GBM), which shows a dimorphic population of glial and mesenchymal elements. The cytopathology of GS to our knowledge has not been previously described. Although prognostically insignificant within the group of GBM, an accurate recognition of this subtype may help to rule out other morphologically similar primary and metastatic central nervous system (CNS) neoplasms. Thirteen cases of histologically confirmed GS with concomitant touch imprints (TI) or prior fine-needle aspiration (FNA) were retrieved from the files of The Johns Hopkins Hospital (1985-2002). A comprehensive review of the clinico-radiologic, cytologic, and histologic material was undertaken to define the morphologic characteristics of GS. Material was obtained via computerized tomography (CT)-guided needle biopsy. Slides were stained with DiffQuik and/or hematoxylin and eosin (H and E) stains. Smears were highly cellular and showed a high-grade neoplasm with glial and mesenchymal elements. The latter component, however, predominated and showed a variety of phenotypic patterns, which included fibrosarcoma-like, rhabdoid type, osteoclastic giant cell type, undifferentiated type, and tumor with heterologous components (such as chondroid or osteoid tissue). A rich arborizing capillary network was evident, as were a high mitosis/karyorrhexis index and foci of necrosis. The glial component consisted of pleomorphic round to oval nuclei and numerous gemistocytes embedded in a fibrillary stroma.

Adult↗
PubMed2004

Molecular diagnosis of metastasizing oligodendroglioma: a case report.

We report the case of a suspicious parotid mass in which molecular determination of loss of heterozygosity (LOH) of chromosome arms 1p and 19q in combination with cytologic and immunohistochemical analysis defined the tumor to be metastatic oligodendroglioma. The patient was a 41-year-old woman who developed a World Health Organization grade II oligodendroglioma in her right frontal lobe at age 32, for which no adjuvant chemo- or radiotherapy was administered. Five years following this diagnosis, radiological assessment revealed a 10-centimeter mass in the tumor bed, suspicious for a recurrence. Resection of this lesion revealed an anaplastic oligodendroglioma (grade III) and adjuvant radiotherapy was given. Eleven months after this surgery the patient presented with a 5.5-cm subcutaneous, non-mobile, non-tender mass in the region of the right parotid gland. Fine needle aspiration (FNA) yielded highly cellular material, morphologically and immunohistochemically suspicious for oligodendroglioma. Molecular analysis of microsatellite loci residing on chromosome arms 1p and 19q was performed using DNA extracted from the patient's recurrent brain oligodendroglioma and the FNA specimen. This analysis revealed evidence of LOH at all eight of the microsatellite loci tested. The combination of cytologic and molecular findings defined the extracranial tumor to be metastatic oligodendroglioma.

Adult↗
PubMed2004

Histopathological and molecular prognostic markers in medulloblastoma: c-myc, N-myc, TrkC, and anaplasia.

Several molecular and histopathological prognostic markers have been proposed for the therapeutic stratification of medulloblastoma patients. Amplification of the c-myc oncogene, elevated levels of c-myc mRNA, or tumor anaplasia have been associated with worse clinical outcomes. In contrast, high TrkC mRNA expression generally presages longer survival. The goal of this study was to evaluate the prognostic value of c-myc, N-myc and TrkC expression in medulloblastomas and compare them to histopathological classification. We used in situ hybridization to measure expression of these molecular markers. c-myc mRNA was detected in 18 of 59 (31%) cases, and was significantly associated with shorter patient survival times on both univariate and multivariate analyses (p = 0.04). The presence of c-myc mRNA was also significantly associated with tumor anaplasia. While survival rates were higher for patients with low N-myc or high TrkC expression, these differences were not statistically significant. The group of patients with either moderate or severely anaplastic tumors showed only a trend towards shorter survival (p = 0.11). However, severe anaplasia alone was significantly prognostic (p = 0.002). Given the prognostic import of c-myc, we investigated 2 potential mechanisms by which its expression might be regulated: Wnt signaling and Mxi-1 mutation. Nuclear translocation of beta-catenin, a marker of Wnt pathway activation, was more common in medulloblastomas with high c-myc than in tumors overall, but the difference was not statistically significant. No Mxi-1 mutations were detected in the 22 cases examined. The association we describe between c-myc expression, tumor anaplasia, and worse clinical outcomes provides further evidence for the importance of this oncogene in medulloblastoma pathobiology.

Active Transport, Cell Nucleus↗
PubMed2004

Immunohistochemical detection of EGFRvIII in high malignancy grade astrocytomas and evaluation of prognostic significance.

The purpose of this study was to establish an accurate and accessible immunohistochemical (IHC) method for detecting vIII Egf receptor and to assess the prognostic significance of the method as applied to the detection of vIII in malignant astrocytomas. The accuracy of the method was determined by comparing vIII immunoreactivity in formalin-fixed and paraffin-embedded tumor sections versus RT-PCR results from the analysis of RNA extracted from corresponding frozen specimens. RT-PCR revealed vIII transcript in 18 of 44 cases in this series, and IHC analysis of matched formalin-fixed and paraffin-embedded sections showed EGFRvIII reactivity in each of these 18 tumors, as well as 1 additional tumor that was negative for vIII transcript. EGFR amplification was evident in all tumors expressing vIII; none of the 15 tumors lacking amplified EGFR were positive for vIII transcript or vIII protein. IHC analysis for vill expression was next applied to a large series of anaplastic astrocytomas (AAs) and glioblastoma multiforme (GBMs) from clinical trial patients with complete follow-up and that had been previously examined by FISH for amplified EGFR. Among the GBMs, vIII detection by IHC was determined in 19 of 46 cases (41.3%) with EGFR amplification, and in only 3 of 59 tumors lacking amplified EGFR (5.1%). Among the AAs, vIII expression was observed in 3 of 14 cases with amplified EGFR (21.4%) and in 6 of 49 cases without EGFR amplification (12.2%). GBM and AA patient survival analysis as a function of vIII expression showed contrasting results, with vIII positivity having no association with survival among GBM patients (p = 0.84), but being highly associated with reduced survival among AA patients (p = 0.0016). This latter finding, though quite possibly a result of vIII's association with increasing AA patient age, suggests that vIII IHC will be useful for identifying and/or confirming the identity of malignant astrocytomas whose clinical behavior is consistent with that of GBM.

Adult↗
PubMed2004

Transmission of glioblastoma multiforme following bilateral lung transplantation from an affected donor: case study and review of the literature.

Donor-acquired solid organ malignancy is a rare complication of organ transplantation. We report a case of a patient who received bilateral lung transplants for pulmonary fibrosis from a donor with known glioblastoma multiforme (GBM). The lungs, heart, liver, and kidneys were harvested after a lethal intracranial bleed and accepted for transplantation by four centers. An enlarged hilar lymph node sampled at the time of transplant was found to contain GBM. Four months later, the patient developed diffuse interstitial pulmonary infiltrates with mediastinal lymphadenopathy. Lung biopsy confirmed metastatic GBM. The patient died 2 weeks after the diagnosis was established. The patient receiving the donor liver also developed GBM. We present a case study, review of the literature, and suggested interventions to minimize the risk of transmission.

Adult↗
PubMed2004

Pilocytic and pilomyxoid hypothalamic/chiasmatic astrocytomas.

OBJECTIVE: Pilocytic astrocytoma (PA) is a common type of pediatric brain tumor that can arise within the hypothalamic/chiasmatic region and typically has an excellent outcome. We identified a group of tumors, previously classified as PAs, with unique histological features and aggressive behavior. This article describes the clinicopathological features of these unusual neoplasms, which are currently known as pilomyxoid astrocytomas (PMAs), to better differentiate them from typical PAs. METHODS: Medical information and surgical specimens were obtained for 42 PA cases and 21 PMA cases. Patient demographic features, treatment modalities, progression-free survival (PFS) times, overall survival (OS) times, and outcomes were compared between the groups with nonparametric tests. RESULTS: The PMA group included 12 male and 9 female patients. The PA group included 27 male and 15 female patients. The mean ages at diagnosis for the PMA and PA groups were 18 months (range, 2-84 mo) and 58 months (range, 4-189 mo), respectively (P < 0.01). The mean PFS times for the PMA and PA groups were 26 and 147 months, respectively (P < 0.001). The mean OS times for the PMA and PA groups were 63 and 213 months, respectively (P < 0.001). Sixteen patients with PMAs (76%) experienced local recurrence, and three of those patients demonstrated evidence of cerebrospinal fluid dissemination. Twenty-one patients with PAs (50%) experienced local recurrence, none with evidence of cerebrospinal fluid dissemination. Within the follow-up period, seven patients with PMAs (33%) and seven patients with PAs (17%) died as a result of their disease. In an age-matched set, the mean PFS times for the PMA and PA groups were 25 and 163 months, respectively (P < 0.01), and the mean OS times for the PMA and PA groups were 60 and 233 months, respectively (P < 0.001). CONCLUSION: Hypothalamic/chiasmatic PMAs occurred in a significantly younger population and were associated with substantially shorter PFS and OS times than were typical PAs. Increased recognition of these lesions could affect the prognosis and treatment of pediatric astrocytomas.

Adolescent↗
PubMed2004

Hypertrophic neuropathy of the cauda equina: case report.

OBJECTIVE AND IMPORTANCE: Hypertrophic neuropathy of the cauda equina (HNCE) is a rare form of peripheral neuropathy. The diagnosis is complicated by an insidious clinical presentation and complex radiographic images. We present a case of HNCE caused by chronic inflammatory demyelinating polyneuropathy with symptomatic improvement after decompressive lumbar laminectomy and dural expansion. CLINICAL PRESENTATION: A 54-year-old woman with a history of back pain since she was in her 20s presented with low back and radicular pain that had increased during a period of 6 months, bilateral lower-extremity weakness, and sensory loss in the right thigh. Magnetic resonance imaging of the lumbosacral spine revealed multiple, poorly enhancing mass lesions and apparent intrathecal nerve root thickening from L1 to L5. INTERVENTION: An L1-L5 decompressive laminectomy, performed with continuous somatosensory evoked potential and electromyographic monitoring, revealed multiple segmentally enlarged nerve roots. One nerve root that did not respond to high levels of stimulation was identified. This root was resected and submitted for pathological analysis. The dura was expanded with an 11-cm-long dural patch. The pathological examination revealed hypertrophic neuropathy, with extensive S-100-positive "onion bulb" formation. The patient's symptoms improved postoperatively. CONCLUSION: HNCE is a rare disorder that can cause radicular pain and lower-extremity weakness, sensory loss, and hyporeflexia. One possible cause is demyelinating polyneuropathy. Although medical management is typically effective in the treatment of demyelinating polyneuropathy, it has little effect on compressive symptoms caused by intradural nerve root enlargement. As this case demonstrates, surgical management of symptomatic radiculopathy by lumbar laminectomy is a reasonable and effective approach to the treatment of HNCE.

Cauda Equina↗
PubMed2004

Imaging findings of CNS atypical teratoid/rhabdoid tumors.

Four patients with brain tumors were diagnosed with atypical teratoid/rhabdoid tumors and underwent CT and MR imaging. For all tumors, aggressive features were shown by imaging studies and included hydrocephalus, apparent invasion of the adjacent brain and dura, and marked mass effect. The striking heterogeneity of the atypical teratoid/rhabdoid tumor shown by imaging studies reflects the histopathologic complexity of these tumors, and awareness of atypical teratoid/rhabdoid tumor is important in making the correct diagnosis of this uncommon but probably underdiagnosed entity.

Adolescent↗
PubMed2003

Platelets in inflammation and thrombosis.

For many years it has been known that platelets play an important role in thrombosis and hemostasis. In recent times, however, it has become evident that platelets also have relevant functions in inflammation. It was shown that thrombosis and inflammation share several key molecular mechanisms and in fact are 2 intrinsically linked processes. In this review, we intend to give a short overview with emphasis on work stemming from our laboratory.

Animals↗
PubMed2003

Outcome of children with centrally reviewed low-grade gliomas treated with chemotherapy with or without radiotherapy on Children's Cancer Group high-grade glioma study CCG-945.

BACKGROUND: The objectives of the current study were to determine the outcome of children who were treated with chemotherapy and radiotherapy on the Children's Cancer Group (CCG) high-grade glioma protocol (CCG-945) who were diagnosed with low-grade gliomas on post hoc central pathologic review and to identify clinical and biologic features associated with prognosis. METHODS: Between 1985 and 1991, 250 children with institutionally classified high-grade gliomas were enrolled on CCG-945. Patients older than 24 months with intracranial lesions were assigned randomly to receive either lomustine, vincristine, and prednisone (control regimen) or the 8-drugs-in-1-day regimen (experimental regimen); younger patients and those with primary spinal cord tumors were assigned nonrandomly to the experimental regimen. Central independent review by 5 neuropathologists led to a reclassification of low-grade glioma in 70 patients, who were the focus of the current study. RESULTS: The study involved 42 males and 28 females (median age, 7.7 years) with a median follow-up of 10.4 years. At 5 years, the progression-free survival (PFS) rate was 63% +/- 6%, and the overall survival (OS) rate was 79% +/- 5%, compared with a PFS rate of 19% +/- 3% (P < 0.0001) and an OS rate of 22% +/- 3% (P < 0.0001) in the remainder of the cohort. Significantly poorer 5-year PFS was seen in children younger than 24 months, those with fibrillary astrocytoma, and those with posterior fossa tumors. Patients demonstrated a modest improvement in PFS but no improvement in OS compared with children with low-grade gliomas who were treated with contemporary chemotherapy-alone approaches. CONCLUSIONS: The current report calls attention to the importance of central pathologic review in large multiinstitutional trials of children with gliomas and suggests that aggressive front-line combined chemoradiotherapy does not confer a survival advantage in this highly selected population of patients.

Adolescent↗
PubMed2003

Metalloproteinase inhibitors improve the recovery and hemostatic function of in vitro-aged or -injured mouse platelets.

Platelet transfusions are a crucial component of support for patients with severe thrombocytopenia. Storage of platelet concentrates, however, is associated with a reduction in platelet posttransfusion recovery and hemostatic function. In this study, we established a model of mitochondrial injury that resembles platelet storage lesion. Mitochondrial injury, provoked by incubation of platelets with carbonyl cyanide m-chlorophenylhydrazone (CCCP), led to reduced posttransfusion recovery in mice, an effect that directly correlated with the duration of treatment. Damaged platelets were characterized by shape change, disruption of membrane asymmetry, surface expression of P-selectin, and profound proteolysis of GPIbalpha. Using our model, we identified a key role for endogenous metalloproteinase(s) in platelet clearance, as their inhibition markedly improved posttransfusion recovery of both the mitochondria-injured and in vitro-aged mouse platelets. Metalloproteinase inhibition also prevented proteolysis of GPIbalpha on damaged platelets, thereby improving the hemostatic function of these cells in vivo. We propose that inhibition of metalloproteinase activity during storage could significantly improve the effectiveness of platelet transfusions. Surface expression of GPIbalpha might be a powerful marker to determine the quality of platelet concentrates, because it reflects metalloproteinase activity in vitro.

Animals↗
PubMed2003

Rhabdoid meningioma: cytopathologic findings in cerebrospinal fluid.

Rhabdoid meningioma is a recently described, rare, WHO Grade III intracranial tumor with an aggressive growth pattern and increased risk of recurrence. We describe the cytopathologic findings on cerebrospinal fluid of one such case in a 26-yr-old female who underwent resection of a left temporo-parietal mass. Cerebrospinal fluid contained abundant malignant cells with a prominent "rhabdoid" phenotype, i.e., large cells, eccentric nuclei, single prominent nucleoli, and dense eosinophilic cytoplasm. Although rhabdoid meningioma has a characteristic cytomorphology, the differential diagnosis of this tumor would involve metastatic adenocarcinoma, metastatic malignant melanoma, and other tumors with "rhabdoid" features (such as an atypical teratoid/rhabdoid tumor).

Adult↗
PubMed2003

hTERT gene amplification and increased mRNA expression in central nervous system embryonal tumors.

High-level gains at 5p15, a chromosomal region including the human telomerase catalytic protein subunit (hTERT) gene, have been documented in several medulloblastomas. We therefore analyzed hTERT gene dosage in a group of medulloblastomas and other embryonal brain tumors using differential PCR. Amplification of the hTERT locus was detected in 15 of 36 (42%) tumors examined. To correlate gene amplification with message level, we used real-time quantitative PCR to measure hTERT mRNA in 50 embryonal brain tumors. hTERT mRNA was detected in all but one of these cases, and mRNA level correlated significantly with gene dosage (r = 0.82). Log-rank analysis of survival data revealed a trend toward poor clinical outcomes in patients with medulloblastomas containing high hTERT mRNA levels, but clinical follow-up was relatively short and the association was not statistically significant (P = 0.078). Comparative genomic hybridization was used to further analyze the tumor with the greatest hTERT gene dosage and mRNA level, a recurrent medulloepithelioma. hTERT was amplified in the recurrent tumor but not in the primary lesion, suggesting this locus can be involved in tumor progression. Our data indicate that hTERT gene amplification is relatively common in embryonal brain tumors, and that increased expression of hTERT mRNA may be associated with biologically aggressive tumor behavior.

Adolescent↗