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B W Scheithauer

Publications and source records attributed to B W Scheithauer.

At least 73 records · Page 4Linked to original sources
PubMed2000

Spontaneous involution of pilocytic astrocytoma in a patient without neurofibromatosis type 1: case report.

Serial magnetic resonance imaging findings are described in a patient with a sporadically occurring pilocytic astrocytoma that underwent spontaneous regression over 6 years. To the authors' knowledge, this is the first report in which spontaneous involution of a pilocytic astrocytoma not associated with neurofibromatosis type 1 has been described. A literature review regarding sporadic and syndrome-associated pilocytic astrocytoma was undertaken, with particular reference to treatment and natural history.

Adult↗
PubMed2000

Subcellular localization of leptin in non-tumorous and adenomatous human pituitaries: an immuno-ultrastructural study.

Leptin is a key mediator in the maintenance of neuroendocrine homeostasis. Recently, leptin and leptin receptor expression were demonstrated in non-tumorous and adenomatous human pituitaries. This study was performed to determine the subcellular localization of leptin in human adenohypophyses (n = 3) and in various types of pituitary adenoma (n = 16). Immunoelectron microscopy showed leptin immunolabeling in most hormone-producing cells of the human non-tumorous adenohypophysis, but not in stellate cells. Labeling was noted over secretory granules. Immunocytochemistry using double labeling revealed leptin expression in GH-, ACTH-, TSH-, and FSH/LH-containing cells but not in PRL cells. The percentage of immunopositive cells and the intensity of immunostaining varied considerably among the various cell types. Immunoelectron microscopy with double gold labeling showed co-localization of leptin and adenohypophysial hormones in the same secretory granules. Among pituitary tumors, leptin immunolabeling was evident only in corticotroph adenomas. Compared to non-tumorous corticotrophs, leptin immunoexpression was less abundant in corticotroph adenomas. The presence of leptin and adenohypophysial hormones in the same secretory granules suggests that leptin is secreted concomitantly with various adenohypophysial hormones and that its release is under the control of hypothalamic stimulating and inhibiting hormones.

Adenoma↗
PubMed2000

Alterations of chromosome arms 1p and 19q as predictors of survival in oligodendrogliomas, astrocytomas, and mixed oligoastrocytomas.

PURPOSE: A recent report suggests that alterations of chromosome arms 1p and 19q are associated with chemotherapeutic response and overall survival in anaplastic oligodendroglioma patients treated with procarbazine, lomustine, and vincristine chemotherapy. We set out to further clarify the diagnostic and prognostic implications of these alterations in a broader set of diffuse gliomas, including astrocytic neoplasms and low-grade oligodendrogliomas. PATIENTS AND METHODS: Fluorescence in situ hybridization (FISH) signals from DNA probes mapping to 1p and 19q common deletion regions were enumerated in 162 diffuse gliomas (79 astrocytomas, 52 oligodendrogliomas, and 31 mixed oligoastrocytomas), collected as part of an ongoing prospective investigation of CNS tumors. RESULTS: The oligodendroglial phenotype was highly associated with loss of 1p (P =.0002), loss of 19q (P <.0001), and combined loss of 1p and 19q (P <.0001). Combined loss of 1p and 19q was identified as a univariate predictor of prolonged overall survival among patients with pure oligodendroglioma (log-rank, P =.03) and remained a significant predictor after adjusting for the effects of patient age and tumor grade (P <.01). This favorable association was not evident in patients with astrocytoma or mixed oligoastrocytoma. CONCLUSION: Combined loss of 1p and 19q is a statistically significant predictor of prolonged survival in patients with pure oligodendroglioma, independent of tumor grade. Given the lack of this association in patients with astrocytic neoplasms and the previously demonstrated chemosensitivity of oligodendrogliomas, a combined approach of histologic and genotypic assessment could potentially improve existing strategies for patient stratification and management.

Adolescent↗
PubMed2000

Intrasellar chordomas mimicking pituitary adenoma.

OBJECT: Whereas chordomas involving the sellar region are uncommon, largely or entirely intrasellar examples are rare. The goal in this study was to present examples of these rare tumors as a guide to their proper diagnosis and treatment. METHODS: The authors report three cases in which the chordomas filled the pituitary fossa and presented as nonfunctioning pituitary adenomas. All lesions exhibited the typical histological patterns and immunophenotype of chordoma. One tumor, studied ultrastructurally and subjected to DNA analysis, was shown to have a diploid histogram. The authors present a clinicopathological study of these three cases and review the literature on intrasellar chordomas. CONCLUSIONS: Although these tumors are easily misdiagnosed and therefore may not receive optimal treatment, aggressive surgical resection can yield a favorable prognosis in lesions with a limited extent.

Adenoma↗
PubMed2000

Medulloblastomas with extensive posttherapy neuronal maturation. Report of two cases.

The authors report on two patients with classic medulloblastoma, each of whom underwent extensive therapy-associated neuronal maturation. The first patient presented at 3 months of age with hydrocephalus caused by a 5-cm tumor in the cerebellar vermis. He underwent a gross-total resection of a desmoplastic medulloblastoma. No mature elements were identified. Despite adjuvant chemotherapy, a 1.5-cm recurrent tumor developed 6 months later. Sections from the subtotally resected tumor demonstrated exclusively mature neuronal elements, ranging from neurocytes to ganglion cells. Four months later, a second recurrent tumor was resected. The specimen collected this time demonstrated classic medulloblastoma morphological characteristics. The patient was subsequently treated with radiation therapy, which seemed to have an effect; however, the tumor eventually progressed and the patient died. The second patient presented at 3 years of age with a midline medulloblastoma and was treated with subtotal resection, radiation therapy, and chemotherapy. Although the tumor remained stable on radiographic imaging, a second resection was performed 8 years later to alleviate hydrocephalus. Histological examination revealed predominantly small mature neurons with scattered ganglion cells and extensive calcification. No adjuvant therapy was given and the patient is alive and well as of his last follow-up examination. The mature neuronal neoplasms resected in both patients demonstrated negligible proliferative indices and stained appropriately with neuronal immunohistochemical markers. The smaller neuronal population resembled those of a central neurocytoma and medullocytoma/cerebellar neurocytoma. Analogous to neuroblastoma, our cases suggest that adjuvant therapy can induce extensive or complete neuronal maturation in medulloblastoma. Additional cases must be studied to determine the prognostic significance of this rare phenomenon.

Adolescent↗
PubMed2000

Multiple hemangiomas (hemangiomatosis) of the cauda equina and spinal cord. Case report.

A case of multiple hemangiomas of the cauda equina nerve roots, conus medullaris, and lower spinal cord is described. The 74-year-old male patient presented with a 9-month history of progressive bilateral leg weakness. He had a history of lymphoma at the age of 39 years and renal cell carcinoma in his early 40s. Neither disease was evident at the time of this presentation. A magnetic resonance image revealed multiple enhancing nodules in the cauda equina region as well as on the pial surface of the lower thoracic spinal cord and conus medullaris. The patient underwent an L2-3 laminectomy. Cauda equina nerve roots were found to be studded with numerous purple nodules, the largest measuring 6 to 8 mm. The nodules were adherent to nerve roots from which they could not be resected. Two lesions were histologically examined and found to be capillary hemangiomas. Twelve months into an uneventful postoperative course, the patient is neurologically unchanged. This unique case might represent a distinct form of hemangiomatosis confined to the cauda equina nerve roots and spinal cord.

Aged↗
PubMed2000

Capillary hemangioma of the spinal cord. Report of four cases.

The authors describe the clinicopathological features of four cases of capillary hemangioma of the spinal cord. All occurred in adult patients. The presenting symptoms were similar to those of more common intramedullary tumors. Radiologically, they resemble other vascular spinal cord tumors. All patients underwent surgery, and the outcomes varied. Histologically, the lesions resembled capillary hemangioma of skin or of soft tissue that is composed of lobules of small capillaries with associated feeding vessels, all enveloped by a delicate fibrous capsule. Capillary hemangiomas of the central and peripheral nervous system are extremely rare. Although examples of these lesions have been described as occurring in the dura mater and in peripheral nerve, including spinal nerve roots, none has occurred within the spinal cord. Knowledge of their existence may help practitioners to avoid misdiagnosis of tumor and resultant overtreatment of these benign lesions.

Adult↗
PubMed1999

Nonvasculitic autoimmune inflammatory meningoencephalitis (NAIM): a reversible form of encephalopathy.

Five patients, age 54 to 80 years, presented between 3 weeks and 18 months after symptomatic onset of progressive cognitive decline, psychosis, and unsteady gait that proved to be due to a steroid-responsive nonvasculitic autoimmune inflammatory meningoencephalitic syndrome. CSF examination showed elevated immunoglobulin (Ig)G index and IgG synthesis rate in all three patients in whom it was checked, and brain biopsy revealed perivascular lymphocytic infiltrates without vessel wall invasion.

Aged↗
PubMed1999

Clinicopathologic study of 85 similarly treated patients with anaplastic astrocytic tumors. An analysis of DNA content (ploidy), cellular proliferation, and p53 expression.

BACKGROUND: The biologic behavior of anaplastic (World Health Organization Grade III) astrocytomas and oligoastrocytomas is highly variable, ranging from rapid progression to prolonged survival. It is difficult to predict the outcome of an individual patient based on morphology alone. METHODS: To determine the prognostic value of commonly used clinicopathologic markers, we reviewed our experience with 85 similarly treated patients enrolled in 3 North Central Cancer Treatment Group high grade glioma protocols. The pathology was comprised exclusively of primary anaplastic astrocytic tumors (66 astrocytomas and 19 oligoastrocytomas). Variables examined included patient age, morphologic type, preoperative performance score, extent of surgery, solitary versus multiple mitoses, DNA flow cytometric and image morphometric parameters, and expression of proliferating cell nuclear antigen, MIB-1, and p53 expression. RESULTS: The study was comprised of 48 men and 37 women ranging in age from 14-79 years (median age, 47 years). Overall survival ranged from <1 month to >12 years (median, 21.6 months). Statistical analyses revealed that age accounted for the majority of this extensive variability in survival. The median survival times were 65. 5 months, 22.1 months, and 4.4 months, respectively, for the groups <40 years, 40-59 years, and >/=60 years, respectively (P < 0.0001). On univariate analyses, aneuploidy by flow cytometry and a low performance score also predicted a better survival (P values of 0.04 and 0.009, respectively). Statistical trends predicting a better survival were observed for patients with a solitary mitosis and p53 immunopositivity. However, only patient age remained significant in multivariate models. CONCLUSIONS: In a small but relatively uniformly treated cohort of patients with anaplastic astrocytomas and oligoastrocytomas, patient age was associated strongly and inversely with overall survival. Once patient age was taken into account, the clinical and pathologic markers tested appeared to be of limited prognostic value.

Adolescent↗
PubMed1999

Neurofibroma of the urinary bladder.

BACKGROUND: Neurofibroma of the urinary bladder is rare. Only isolated case reports have appeared. Information regarding the long term follow-up of patients with neurofibroma is limited. METHODS: The authors studied 4 cases of neurofibroma of the bladder diagnosed at Mayo Clinic from 1965 through 1990. Immunostains for S-100 protein, neurofilament protein, epithelial membrane antigen (EMA), cytokeratin (CAM 5.2; AE 1/3), Type IV collagen, MIB-1, and p53 protein were performed in all cases, as was Alcian blue at pH 2.5. The mean follow-up was 9.6 years (range, 2-18 years). RESULTS: The mean age at diagnosis was 17 years (range, 7-28 years); the male-to-female ratio was 1:1. All four patients exhibited physical stigmata of neurofibromatosis type 1. Clinical presentations included hematuria (one patient), irritative symptoms (two patients), and pelvic mass (one patient). Long term urinary complications included bladder atony (two patients), neurogenic bladder (one patient), and recurrent urinary tract infection with hematuria (one patient). Subsequently, two patients underwent partial cystectomy and one a complete cystectomy. Involvement of the bladder was generalized in all four cases. Three tumors were transmural, showing a diffuse and plexiform pattern of growth; in the fourth case, a superficial biopsy showed only diffuse submucosal growth with conspicuous pseudo-Meissnerian corpuscle formation. An Alcian blue positive, variably collagenized matrix was present in all cases. Tumor cells displayed immunoreactivity for S-100 protein and Type IV collagen in all cases. Neurofilament protein positive axons were evident in three cases; all other immunostains were negative. The mean MIB-1 labeling index was 3.2% (range, 0.9-7.3%). No malignant transformation was observed during a mean follow-up of 9.6 years. CONCLUSIONS: Neurofibroma of the bladder presents early in life, is of the plexiform type with a diffuse component, and usually occurs in the setting of generalized neurofibromatosis type 1 rather than as isolated visceral neurofibromatosis. Malignant transformation did not occur in any of these 4 patients during a mean follow-up time of 9.6 years.

Adolescent↗
PubMed1999

Localization of common deletion regions on 1p and 19q in human gliomas and their association with histological subtype.

Allelic alterations of chromosomes 1 and 19 are frequent events in human diffuse gliomas and have recently proven to be strong predictors of chemotherapeutic response and prolonged survival in oligodendrogliomas (Cairncross et al., 1998; Smith et al., submitted). Using 115 human diffuse gliomas, we localized regions of common allelic loss on chromosomes 1 and 19 and assessed the association of these deletion intervals with glioma histological subtypes. Further, we evaluated the capacity of multiple modalities to detect these alterations, including loss of heterozygosity (LOH), fluorescence in situ hybridization (FISH), and comparative genomic hybridization (CGH). The correlation coefficients for detection of 1p and 19q alterations, respectively, between modalities were: 0.98 and 0.87 for LOH and FISH, 0.79 and 0.60 for LOH and CGH, and 0.79 and 0.53 for FISH and CGH. Minimal deletion regions were defined on 19q13.3 (D19S412-D19S596) and 1p (D1S468-D1S1612). Loss of the 1p36 region was found in 18% of astrocytomas (10/55) and in 73% (24/33) of oligodendrogliomas (P < 0.0001), and loss of the 19q13.3 region was found in 38% (21/55) of astrocytomas and 73% (24/33) of oligodendrogliomas (P = 0.0017). Loss of both regions was found in 11% (6/55) of astrocytomas and in 64% (21/33) of oligodendrogliomas (P < 0.0001). All gliomas with LOH on either 1p or 19q demonstrated loss of the corresponding FISH probe, 1p36 or 19q13.3, suggesting not only locations of putative tumor suppressor genes, but also a simple assay for assessment of 1p and 19q alterations as diagnostic and prognostic markers.

Astrocytoma↗
PubMed1999

"Malignancy" in meningiomas: a clinicopathologic study of 116 patients, with grading implications.

BACKGROUND: Due to the rarity of malignancy in meningiomas, prior studies have been limited to small series. Controversies regarding the definition of malignant meningioma have complicated matters further. Although histologic anaplasia and extracranial metastasis are established criteria, the former is difficult to define and the latter represents a clinical finding. Traditionally, brain invasion has also been accepted, although this has recently been debated. In a prior series, the authors were unable to prove that 23 meningiomas that had invaded the brain were more aggressive than atypical meningiomas. METHODS: The authors expanded their analysis to include 116 patients diagnosed with "malignant meningioma" due to brain invasion, frank anaplasia (20 mitoses per 10 high-power fields or histology resembling carcinoma, sarcoma, or melanoma), and/or extracranial metastasis. Patients were followed until death or for a median of 3.7 years. RESULTS: Survival time was highly variable, ranging from 10 days to 24 years. In multivariate analysis, histologic anaplasia (P=0.0035), subtotal resection (P=0.0038), 20 mitoses per 10 high-power fields (P=0.0071), and nuclear atypia (P=0.0068) were associated with poor survival. Of the 89 cases of meningioma that had invaded the brain, 23% were otherwise benign, 61% were otherwise atypical, and 17% were frankly anaplastic. Those without anaplasia behaved similarly to atypical meningiomas from the authors' prior study. In contrast, anaplastic meningiomas were usually fatal, associated with a median survival of 1.5 years. CONCLUSIONS: Based on these findings, the authors suggest that brain invasion constitutes an additional criterion for the diagnosis of atypical meningioma (World Health Organization [WHO] Grade II), whereas frank anaplasia indicates high grade (WHO Grade III-IV) malignancy.

Adolescent↗
PubMed1999

Pleomorphic xanthoastrocytoma: what do we really know about it?

BACKGROUND: Pleomorphic xanthoastrocytomas (PXA) may recur and demonstrate aggressive clinical behavior with a mortality rate between 15% and 20%. To the authors' knowledge, no histopathologic features currently are known to reliably predict recurrence or tumor progression. METHODS: The study was based on 71 cases with available information regarding clinical and therapeutic data and follow-up. Diagnostic features included cellular pleomorphism, giant and/or xanthic cells, eosinophilic granular bodies, desmoplasia, and leptomeningeal involvement. The mitotic index (MI), the presence of necrosis, and endothelial proliferation were recorded in all primary resection specimens. RESULTS: The study included 35 females and 36 males, age 26+/-16 years (mean +/- standard deviation). Approximately 98% of tumors were supratentorial, with 49% in the temporal lobe. Seizures were the presenting symptoms in 71% of patients. Extent of tumor removal was macroscopic total resection in 68% of cases and subtotal resection (STR) in 32% of cases. Postoperative radiotherapy, alone or with chemotherapy, was administered in 29% and 12.5% of cases, respectively. The recurrence free survival rates (RFS) were 72% at 5 years and 61% at 10 years, whereas overall survivals rates (OS) were 81% at 5 years and 70% at 10 years. In univariate analysis, the extent of resection was the single factor associated most strongly with RFS (P=0.003), followed by MI (P=0.007) and atypical mitoses (P=0.04). Necrosis was not found to be significant. The extent of resection and MI were confirmed as independent predictors of RFS by multivariate analysis. MI (P=0.001), atypical mitoses (P=0.02), and necrosis (P=0.04) were associated with OS by univariate analysis. In multivariate analysis, only MI was an independent predictor of survival. Information regarding MIB-1 labeling index and the use of adjuvant therapy was too limited to explore their prognostic significance confidently. CONCLUSIONS: The study confirms that PXA is an astrocytic tumor with a relatively favorable prognosis. MI and extent of resection appear to be the main predictors of RFS and OS. Given the slow growth of the tumor, more studied cases and longer periods of follow-up will be essential to confirm our findings regarding prognostic factors affecting this unusual tumor.

Adolescent↗
PubMed1999

Sex- and age-related differences in ceramide dihexosides of primary human brain tumors.

Neutral glycolipids (NGL) are promising diagnostic markers of human gliomas, but differences in NGL with age and sex have not been examined. Previous work demonstrated that ceramide dihexosides (CDH) levels in mouse kidney are age- and sex-dependent, probably due to levels of sex hormones. We quantitated CDH in 181 human gliomas and found significant differences with sex and age, particularly menopause and male puberty. This emphasizes the importance of assessing results of studies on glycolipids in disease states with respect to age and sex in order to avoid erroneous conclusions concerning the relationship of glycolipid composition with diagnosis and pathogenesis.

Adolescent↗
PubMed1999

p27kip1: a multifunctional cyclin-dependent kinase inhibitor with prognostic significance in human cancers.

p27kip1 (p27) is a member of the universal cyclin-dependent kinase inhibitor (CDKI) family. p27 expression is regulated by cell contact inhibition and by specific growth factors, such as transforming growth factor (TGF)-beta. Since the cloning of the p27 gene in 1994, a host of other functions have been associated with this cell cycle protein. In addition to its role as a CDKI, p27 is a putative tumor suppressor gene, regulator of drug resistance in solid tumors, and promoter of apoptosis; acts as a safeguard against inflammatory injury; and has a role in cell differentiation. The level of p27 protein expression decreases during tumor development and progression in some epithelial, lymphoid, and endocrine tissues. This decrease occurs mainly at the post-translational level with protein degradation by the ubiquitin-proteasome pathway. A large number of studies have characterized p27 as an independent prognostic factor in various human cancers, including breast, colon, and prostate adenocarcinomas. Here we review the role of p27 in the regulation of the cell cycle and other cell functions and as a diagnostic and prognostic marker in human neoplasms. We also review studies indicating the increasingly important roles of p27, other CDKIs, and cyclins in endocrine cell hyperplasia and tumor development.

Cell Cycle↗
PubMed1999

Apoptosis in nontumorous and neoplastic human pituitaries: expression of the Bcl-2 family of proteins.

Analyses of apoptosis and of the apoptosis regulatory proteins Bcl-2, Bax, Bcl-X, and Bad were done in 95 nontumorous and neoplastic pituitary tissues by terminal deoxynucleotide transferase-mediated dUTP nick-end labeling (TUNEL), immunohistochemistry, and Western blotting. The apoptotic index was relatively low in all groups but was at least fourfold higher in pituitary carcinomas compared with any other groups. Pituitaries from pregnant and postpartum women had a fivefold higher apoptotic index compared with matched controls from nonpregnant females. Preoperative treatment of adenomas with octreotide or dopamine agonists did not change the apoptotic index significantly. The lowest levels of Bcl-2, Bax, and Bcl-X expression were in pituitary carcinomas as detected by immunostaining. An immortalized human pituitary adenoma cell line, HP75, developed in our laboratory using a replication-defective recombinant human adenovirus with an early large T-antigen, had a much higher level of apoptosis than nontumorous and neoplastic pituitaries. Treatment with transforming growth factor (TGF)-beta1 and protein kinase C (PKC) inhibitors increased apoptosis in this cell line. Analysis of the Bcl-2 family of proteins after treatment with TGF-beta1 and PKC inhibitors showed a 20% to 30% decrease in Bcl-X in the treated groups compared with controls. These results, which represent the first study of apoptosis in pituitaries from pregnant and postpartum cases and in pituitary carcinomas, indicate that 1) the apoptotic rate is low in nontumorous and neoplastic pituitary tissues but is relatively higher in pituitary carcinomas, 2) there are alterations in the expression of the Bcl-2 family of proteins in pituitary neoplasms with a decrease in Bcl-2 expression in pituitary carcinomas that may contribute to pituitary tumor pathogenesis and/or proliferation, and 3) cultured pituitary tumor cells respond to TGF-beta1 and PKC inhibitors by undergoing apoptotic cell death.

Adult↗
PubMed1999

Deletions of the INK4A gene occur in malignant peripheral nerve sheath tumors but not in neurofibromas.

The INK4A gene, a candidate tumor suppressor gene located on chromosome 9p21, encodes two protein products, p16 and p19(ARF). p16 is a negative cell cycle regulator capable of arresting cells in the G1 phase by inhibiting cyclin-dependent kinases 4 (Cdk4) and 6 (Cdk6), thus preventing pRB phosphorylation. p19(ARF) prevents Mdm2-mediated neutralization of p53. Loss of INK4A is a frequent molecular alteration involved in the genesis of several neoplasms, including tumors of neuroectodermal origin. This study investigated the frequency of INK4A gene alterations in a series of malignant peripheral nerve sheath tumors (MPNSTs) and neurofibromas (NFs). INK4A gene and the p19(ARF)-specific exon 1beta were studied in 11 MPNST samples from 8 patients and 7 neurofibromas. Presence of INK4A deletions was assessed by Southern blotting hybridization and by a multiplex polymerase chain reaction (mPCR). INK4A point mutations were examined by single-strand conformation polymorphism (SSCP) and sequencing. The p16 promoter methylation status was determined by PCR amplification of bisulfite-treated DNA. Homozygous deletions of exon 2, thus affecting both p16 and p19(ARF), were identified in MPNSTs from 4 of 8 patients. Deletions, mutations, or silencing by methylation were not identified in the neurofibromas analyzed. Based on our results, we conclude that INK4A deletions are frequent events in MPNSTs and may participate in tumor progression. Silencing of p16 by methylation, which occurs often in several tumor types, is uncommon in MPNSTs.

Blotting, Southern↗