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Peter C Burger

Publications and source records attributed to Peter C Burger.

At least 19 recordsLinked to original sources
PubMed2005

The prognostic impact of histology and 1p/19q status in anaplastic oligodendroglial tumors.

BACKGROUND: It has been reported previously that the combined loss of chromosomal arms 1p and 19q is a significant predictor of outcome for patients with anaplastic oligodendroglial (AO) tumors and that such chromosomal loss correlates with classic histology in AO. The authors sought to determine whether histology was an equivalent or superior predictor of outcome compared with 1p/19q status in 131 patients with AO tumors. METHODS: The status of 1p and 19q was determined using real-time, quantitative polymerase chain reaction analysis and/or fluorescence in situ hybridization. Clinical features (response to adjuvant therapy and tumor location) and molecular genetic abnormalities (9p and 10q deletions, overexpression of p53 and epidermal growth factor receptor) were determined on available specimens. Histologic assessments for classic oligodendroglial features were performed by five neuropathologists. RESULTS: Classic histology was associated closely with 1p/19q loss, as reported previously. Patients who had tumors that were considered classic by at least four of the five neuropathologists showed significantly increased progression-free and overall survival compared with the patients who had less classic tumors. The authors also tested the correlation between 1p/19q status and outcome in subsets of patients stratified according to classic tumor features. The association of 1p/19q status with survival was related closely to the presence of classic histology. Loss of 1p/19q was predictive of improved outcome only among patients who had tumors with classic histologic features. CONCLUSIONS: The current results suggested that, in addition to 1p/19q status, histologic features contribute information to the prediction of outcome in patients with AO. Loss of 1p and 19q appeared to be a prognostic marker only in the subset of patients who had AO tumors with classic histologic features.

Base Sequence↗
PubMed2005

Clinicopathologic and genetic profile of intracranial marginal zone lymphoma: a primary low-grade CNS lymphoma that mimics meningioma.

PURPOSE: Although rare overall, marginal zone B-cell lymphoma (MZBCL) is the most common primary low-grade CNS lymphoma reported in the literature. The aim of this study is to elucidate the biology and genetic features of this unusual tumor. PATIENTS AND METHODS: Fifteen CNS MZBCLs were studied clinically, pathologically, and genetically, including fluorescent in situ hybridization analyses with commercially available MALT1 and IgH break-apart and centromere 3, 7, 12, and 18 probes. RESULTS: CNS MZBCLs preferentially affect middle-aged women (female-to-male ratio, 4:1), with 93% presenting as dural-based masses mimicking meningioma. Ten patients with 1 to 7.6 years of follow-up after diagnosis showed no evidence of disease after radiation and/or chemotherapy. Like MZBCLs outside of the CNS, they consisted of CD20+, CD3- small B lymphocytes with varying degrees of plasmacytic differentiation and predominantly kappa light-chain restriction (78%). Lymphoid follicles with follicular colonization were seen in three patients and deposition of amyloid was noted in samples from two patients, one of which was tumefactive. Neither Bcl-6 protein nor Epstein-Barr virus-encoded RNA was expressed. Trisomy 3 was detected in six of 12 patients, with no rearrangements of MALT1 or IgH and no trisomies of 7, 12, or 18 detected. CONCLUSION: Our data suggest that intracranial MZBCL is an indolent primary CNS lymphoma that typically presents as a meningioma-like dural-based mass. Trisomy 3, but not MALT1 or IgH translocation, is a common genetic abnormality that may contribute to the pathogenesis of this CNS lymphoma.

Adult↗
PubMed2005

Isochromosome 17q is a negative prognostic factor in poor-risk childhood medulloblastoma patients.

BACKGROUND: Medulloblastomas are the most common primary malignant childhood intracranial neoplasms. Patients are currently sorted into three risk groups based on clinical criteria: standard, poor, and infant (<18 months old). We hypothesized that genetic copy number aberrations (CNA) predict prognosis and would provide improved criteria for predicting outcome. METHODS: DNA from 35 medulloblastoma patients from four Children's Cancer Group trials was analyzed by comparative genomic hybridization to determine CNAs. The genetic alterations were evaluated using statistical and cluster analyses. RESULTS: The most frequent CNAs were gains on 17q, 7, 1q, and 7q and losses on 17p, 10q, X, 16q, and 11q. Amplification at 5p15.1-p15.3 was also detected. Isochromosome 17q (i(17)(q10)) was associated with poor overall survival (P = 0.03) and event-free survival (P = 0.04) independent of poor risk group classification. Age <3 tended to be associated with <3 CNAs (P = 0.06). Unsupervised cluster analysis sorted the study patients into four subgroups based on CNAs. Supervised analysis using the program Significance Analysis of Microarrays (SAM) quantitatively validated those CNAs identified by unsupervised clustering that significantly distinguished among the four subgroups. CONCLUSIONS: Medulloblastomas are genetically heterogeneous and can be categorized into separate genetic subgroups by their CNAs using unsupervised cluster analysis and SAM. i(17)(q10) was a significant independent negative prognostic factor. Infant medulloblastomas may be a distinct genetic subset from those of older patients.

Adolescent↗
PubMed2005

Pineal gland lesions: a cytopathologic study of 20 specimens.

BACKGROUND: Pineal gland lesions are rare, with only a few cytologic descriptions occurring in the literature, according to the authors' knowledge. The current article describes the cytopathologic characteristics of 20 such lesions with discussion of differential diagnoses. METHODS: Cytologic material was obtained either by fine-needle aspiration biopsy (FNAB) under stearotactic radiologic guidance or by touch imprinting (TI) at the time of frozen sectioning. The 20 specimens include pineoblastoma (five specimens), pineocytoma (four specimens), astrocytoma (three specimens), germ cell tumor (three specimens), meningioma (one specimen), epidermoid cyst (three specimens), and pineal cyst (one specimen). Smears were stained with Diff-Quik and with Papanicolaou and hematoxylin and eosin stains. In selected specimens, immunoperoxidase (IPOX) stains were performed on cell block sections using synaptophysin, neuron-specific enolase, placental alkaline phosphatase, glial fibrillary acidic protein, leukocyte common antigen, cytokeratins, and human chorionic gonadotropin antibodies. RESULTS: Several cytomorphologic characteristics unique to each lesional category with occasional overlapping features were observed. The unique features included the following: small, hyperchromatic, round to oval cells with frequent rosetting (pineocytoma), with a few specimens in addition showing hypercellularity, crowding, mitoses, and necrosis (pineoblastoma); pleomorphic round cells in a fibrillary background (astrocytoma); large polygonal cells with prominent nucleoli and clear cytoplasm (germ cell tumor); spindled fibroblastic cells (meningioma); anucleate squames and mature squamous cells (epidermoid cyst); and small uniform polygonal cells (pineal cyst). When necessary, IPOX studies supported the morphologic diagnoses. CONCLUSIONS: FNAB and TI cytology were found to provide a rapid and reliable diagnosis of pineal lesions. This is particularly important when dealing with minute amounts of tissue material. Both techniques appeared to provide equally good cytomorphology on smears. IPOX studies played an important complementary role in difficult cases when performed on cell blocks.

Adolescent↗
PubMed2005

Atypical teratoid/rhabdoid tumor of the brain: cytopathologic characteristics and differential diagnosis.

BACKGROUND: Atypical teratoid/rhabdoid tumor (AT/RT) is a highly aggressive neoplasm with a unique cytogenetic profile. Although the clinicopathologic and radiologic features of AT/RT have been described previously, to the authors' knowledge the cytomorphologic profile of this tumor has not been studied well. METHODS: Nine samples of AT/RT from 8 patients were analyzed from the pathology files of 2 large institutions in a 10-year period (1993-2002). Material consisted of slides made from scraping and smearing (SS) or squash preparation (SP) of the tissue cores (six slides), fine-needle aspiration (FNA) (two slides), and cerebrospinal fluid (one slide). Smears were stained with Diff-Quik, Papanicolaou, and hematoxylin and eosin stains. RESULTS: There were 4 males and 4 females who ranged in age from 1-16 years (mean age, 7.1 years). Cytomorphologic features consisted of hypercellularity (eight of eight tumors); predominantly large tissue fragments with tumor cells surrounding proliferating capillaries depicting a "papillary-like" appearance (five of eight tumors); large, round, "plasmacytoid" cells and characteristic "rhabdoid" cells (i.e., intermediate-sized cells with granular to fibrillary, brightly eosinophilic cytoplasm with or without globoid "inclusions"; large, eccentrically located, round-to-reniform nuclei with single prominent nucleoli; eight of eight tumors); small, round, primitive "neuronal-appearing" cells with a high nuclear to cytoplasmic ratio (five of eight patients); and bizarre, multinucleated giant cells (two of eight tumors). Also seen were numerous apoptotic bodies, mitoses, and significant necrosis (seven of eight tumors), and prominent dystrophic calcification (four of eight tumors). CONCLUSIONS: AT/RT is extremely rare. Cytologic examination by SS, SP, or FNA offers a useful alternative to frozen section during intraoperative consultation. Cytomorphologic features are unique and lead to an accurate diagnosis in the right clinicoradiologic context. The differential diagnosis includes medulloblastoma (in cerebellar tumors), primitive neuroectodermal tumor (in suprasellar tumors), choroid plexus carcinoma, and malignant glioma.

Adolescent↗
PubMed2005

Investigation of human brain tumors for the presence of polyomavirus genome sequences by two independent laboratories.

JC virus (JCV), BK virus (BKV) and simian virus 40 (SV40) may be associated with human brain tumors. These polyomaviruses have been shown to induce brain tumors in experimentally infected animals. Several studies have found polyomavirus genomic sequences in human brain tumor tissues by using polymerase chain reaction (PCR), while others have not. Inconsistencies in previous findings may be due in part to small sample sizes and differences in underlying patient populations, laboratory techniques and quality control measures. To assess the role of polyomaviruses in human brain tumors and address inconsistencies of previous reports, we investigated the prevalence of viral sequences in a series of 225 brain tumor tissue specimens in 2 independent laboratories. PCR followed by Southern hybridization was performed at the National Institute of Neurological Disorders and Stroke (NINDS). Real-time quantitative PCR was performed on the same tissues at Johns Hopkins University (JHU). Only those tumors with amplifiable DNA were tested further for polyomavirus sequences. Positive and negative control tissues were included, and all specimens were masked. Amplifiable DNA was detected in 225/225 (100%) tumors at NINDS, 9 (4%) of which contained polyomavirus sequences (3 JCV-positive, 3 BKV-positive and 3 SV40-positive). The JHU laboratory amplified DNA from 165/225 (73%) tumors, of which 1 tumor tested positive (for SV40). No tumors tested positive in both laboratories. Results for masked quality control tissues were concordant between laboratories. Nucleotide sequences for JCV, BKV and SV40 are rarely present in a large series of adult and pediatric brain tumors.

Adolescent↗
PubMed2005

Autoimmune hypophysitis.

Autoimmune (lymphocytic) hypophysitis is a rare disease that should be considered in the differential diagnosis of any nonsecreting pituitary mass, especially when occurring during pregnancy or postpartum. We have analyzed 370 articles published from January 1962 to October 2004 and identified a total of 379 patients with primary lymphocytic hypophysitis. The present review synthesizes the clinical and research data reported in this body of scientific literature.

Animals↗
PubMed2005

Lhermitte-Duclos disease: a report of 31 cases with immunohistochemical analysis of the PTEN/AKT/mTOR pathway.

Lhermitte-Duclos disease (LDD) is a rare cerebellar tumor associated with Cowden disease (CD) and germline mutations in the PTEN gene. To further define these relationships, we reviewed clinical and pathologic findings in 31 LDD cases and analyzed the status of the PTEN pathway in 11 of them. We hypothesized that the granule cell hypertrophy in LDD is secondary to activation of mammalian target of rapamycin (mTOR), a downstream effector in the PTEN/AKT pathway and a major regulator of cell growth. Histopathologically, in addition to the classical findings of LDD, we observed prominent vascular proliferation and vacuolization of the white matter in many of the lesions. Four patients met diagnostic criteria for CD, and many of the remaining patients had some clinical features of CD. Immunohistochemical analysis showed high levels of phospho-AKT and phospho-S6 in the large ganglionic cells forming the lesions, indicating activation of the PTEN/AKT/mTOR pathway and suggesting a central role for mTOR in the pathogenesis of LDD. These data support recommendations for genetic testing and screening for CD in patients with LDD and suggest a novel therapy for LDD through pharmacologic inhibition of mTOR.

Adolescent↗
PubMed2005

INI1 protein expression distinguishes atypical teratoid/rhabdoid tumor from choroid plexus carcinoma.

Central nervous system atypical teratoid/rhabdoid tumor (AT/RT) and choroid plexus carcinoma (CPC) are rare, highly malignant tumors that predominantly arise in infants and young children. Overlapping clinical, histologic, ultrastructural, or immunophenotypic features may obscure the diagnosis in some cases. AT/RT is characterized by deletions and/or mutations of the INI1 tumor-suppressor gene on chromosome band 22q11.2. We have recently developed an INI1 immunohistochemical staining assay. Negative staining of tumor cells resulting from inactivation of the INI1 gene is a consistent feature of AT/RT. Mutations of INI1 in some CPCs have been reported. The purpose of the present study was to determine if immunohistochemical staining with an INI1 antibody would provide a sensitive means of distinguishing between CPC and AT/RT. We examined 28 tumors with a submitted diagnosis of CPC. Twenty-one CPCs showed retained expression of INI1 and seven tumors showed loss of INI1 expression. Cytogenetic, FISH, and/or INI1 mutation results were also available for 13 tumors. In three of the seven cases, monosomy 22 was the only cytogenetic abnormality, suggestive of AT/RT. However, monosomy 22 was also identified in 3 tumors with complex karyotypes that retained INI1 expression. The 7 tumors that were immunonegative for INI1 had features that were consistent with AT/RT. Immunostaining for INI1 protein is retained in the majority of CPC and is lost in AT/RT. This expression pattern seems to better define the 2 groups of tumors than does light or electron microscopy, routine immunohistochemistry, or cytogenetic analysis alone.

Adolescent↗
PubMed2005

Monomorphous angiocentric glioma: a distinctive epileptogenic neoplasm with features of infiltrating astrocytoma and ependymoma.

We present 8 examples of a neoplasm with features of both astrocytoma and ependymoma that may represent a distinct clinicopathologic entity. The cerebral hemispheric tumors occurred in patients that were 3, 4, 12, 14, 15, 26, 30, and 37 years of age. All presented with seizures that, with the exception of 2, began in childhood. Magnetic resonance imaging studies showed ill-defined, T2-hyperintense, generally noncontrast-enhancing lesions that, although centered on the cortex or amygdala, extended into the underlying white matter for a short distance. Histologically, the variably infiltrative tumors were distinctively angiocentric with well-developed perivascular pseudorosettes in some cases. Longitudinal and/or circumferential orientations of perivascular cells were common also. The cells were uniform in their cytologic features from case to case and were bipolar in all but one case. A glial nature was inferred from immunoreactivity for GFAP, and ependymal differentiation was suggested by positivity for EMA in three cases and ultrastructural features in one. Overall, the tumors were biologically indolent except for one that recurred and ultimately proved fatal.

Adolescent↗
PubMed2005

Pharmacotherapy of congestive heart failure in elderly patients.

With longer life expectancy, as well as better survival rates after myocardial infarction, the population of elderly patients with congestive heart failure steadily increases. Large, randomized, placebo-controlled studies have shown significant beneficial effects for several classes of drugs (angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, beta-blockers, aldosterone antagonists) in patients with congestive heart failure. In most of these studies, however, elderly patients were either excluded or represented only a minority of the study population. Therefore, the treatment benefit for the large population of patients aged 65 and older is still not very well documented. In this paper, we critically review the current literature with regard to outcome of heart failure therapy in this particular subpopulation.

Aged↗
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↗