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Biomedical subjects

Joachim M Baehring

Publications and source records attributed to Joachim M Baehring.

At least 19 recordsLinked to original sources
PubMed2007

Primary CNS lymphoma.

Non-Hodgkin's lymphoma invades the brain, the vitreous body and nerves of the eye, the meninges, and the nerve roots of brain and spine, leading to the development of a primary CNS lymphoma. The mechanism of involvement of these locations by malignant B lymphocytes is unknown, but it might involve molecular targeting of lymphoma cells generated at cryptic systemic sites. The diagnosis of primary CNS lymphoma has been facilitated by advances in imaging techniques and the discovery of molecular markers. Methotrexate-based regimens, even when radiation is deferred, prolong overall survival to over 5 years, but relapses eventually occur in most cases. Better tools for earlier diagnosis and monitoring of treatment response will emerge from molecular studies of therapeutic targets.

Central Nervous System Neoplasms↗
PubMed2006

Diffusion MRI in the early diagnosis of malignant glioma.

OBJECTIVE: A subset of patients with malignant glioma comes to medical attention before their masses show rim enhancement and central necrosis. Tumors in those cases are frequently located in eloquent areas of the brain. Tissue diagnosis is limited to stereotactic biopsy providing limited material for accurate grading. We conducted this study to determine whether imaging characteristics of early stages of malignant gliomas could aid in timely definitive diagnosis. METHODS: We retrospectively analyzed patients with newly diagnosed malignant glioma seen at the Yale Brain Tumor Center between 2002 and 2005. Patients with typical radiographic presentation were excluded. RESULTS: Of 89 patients, eight meeting the inclusion criteria were identified. In five patients, patchy or small nodular enhancing lesions without central necrosis were present within the tumor mass. Diffusion-weighted imaging (DWI) showed areas of increased signal intensity in all cases. Apparent diffusion coefficient maps (ADC) revealed low-signal intensity in corresponding areas. At the time of imaging, biopsy was performed in seven patients but diagnosis of malignant glioma could only be established prior to further tumor growth in four cases. CONCLUSIONS: The diagnosis in the early stages of malignant glioma can be challenging in a subset of cases. Information obtained through DWI should be incorporated in the clinical decision-making process. Mass lesions displaying decreased water diffusion indicating high cellularity, are suggestive of a high-grade glioma. Biopsies are recommended. However, even when biopsies are inconclusive, a strong suspicion of malignant glioma should be considered.

Aged↗
PubMed2006

Immunoglobulin gene rearrangement analysis in cerebrospinal fluid of patients with lymphoproliferative processes.

OBJECTIVE: To determine the sensitivity and specificity of clonal immunoglobulin heavy chain gene rearrangement (IGHR) analysis in the distinction of benign and malignant lymphoproliferative diseases. METHODS: A retrospective analysis was conducted of patients in whom a malignant lymphoproliferative process was suspected. Cells of CSF samples were collected by centrifugation, resuspended in 100 microl of the supernatant and boiled. A 10 microl aliquot of this lysate served as template for semi-nested polymerase chain reaction using variable and joining region consensus primers. PCR products were analyzed by polyacrylamide gel electrophoresis. Cytopathological diagnosis and flow cytometry results were recorded. Sensitivity and specificity of IGHR analysis, cytopathology and flow cytometry were calculated. RESULTS: Eleven patients (12 specimens) had involvement of leptomeninges at the time of lumbar puncture. Another 25 cases (27 specimens) had normal CSF findings or were diagnosed with benign lymphoproliferative conditions. Sensitivity of CSF cytopathology, flow cytometry and IGHR analysis were 0.27 [95% confidence interval 0.06, 0.61], 0.1 [0.003, 0.45] and 0.58 [0.28, 0.85]. Specificity was 1 [0.86, 1], 0.95 [0.77, 1.0] and 0.85 [0.66, 0.96]. INTERPRETATION: IGHR analysis appears to be a useful addition to morphological and flow cytometry analysis of cerebrospinal fluid in the evaluation of CNS lymphoproliferative processes.

Adolescent↗
PubMed2006

Multifocal motor neuropathy with conduction block associated with metastatic lymphoma of the nervous system.

Peripheral neuropathies occur in 5% of patients with Non-Hodgkin Lymphoma and represent the effects of therapy, direct compression or nerve infiltration by tumor, or paraneoplastic effects. Multifocal motor neuropathy with conduction block (MMNCB) is a rare demyelinating disorder of unknown etiology characterized by progressive, distal, asymmetric weakness mostly of the upper limbs with minimal or no sensory loss. We report a patient, who developed MMNCB at the time of isolated CNS relapse from a diffuse large B-cell lymphoma. Marked neurological improvement was achieved using intravenous immunoglobulin treatment. To our knowledge, MMNCB has thus far not been described as part of the spectrum of lymphoma-related peripheral neuropathies.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2006

Paraneoplastic subacute sensory neuronopathy secondary to a malignant mixed mullerian tumor.

BACKGROUND: Paraneoplastic subacute sensory neuronopathy is a rapidly progressive autoimmune disorder commonly associated with small cell cancers. Relentless destruction of dorsal root ganglion cells by cytotoxic T cells leads to a poor prognosis. CASE: A 42-year-old woman developed sensory loss in both lower extremities 10 days after debulking of a uterine malignant mixed müllerian tumor. She progressed to sensory loss over the entire body, with initially preserved strength, severe dysmetria, and truncal ataxia. Her serum was positive for antineuronal nuclear antibody-1 (anti-Hu), confirming the diagnosis of paraneoplastic subacute sensory neuronopathy. Despite treatment with intravenous immunoglobulin, methylprednisolone, and plasmapheresis, she remained severely disabled. CONCLUSION: Because neuronal damage is irreversible, early recognition may be the only means to prevent severe neurologic disability.

Adult↗
PubMed2006

Evolution of brain imaging abnormalities in mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes.

An 18-year-old man developed consecutive homonymous hemianopias that were eventually attributed to mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS). The diagnosis was initially suspected when brain CT scans showed bilateral dystrophic basal ganglia calcifications and MR spectroscopy later showed a prominent lactate peak. Diffusion-weighted MRI showed progressive evolution of restricted proton diffusion at the margins of the lesion from day 3 through 3 weeks. Genetic testing from peripheral blood confirmed an A3243G transition in the patient's MTTL1 gene encoding the transfer RNA for leucine. The patient's visual function improved, but severe atrophy of gray and white matter was visible on MRI.

Adolescent↗
PubMed2005

Analysis of clonal immunoglobulin heavy chain rearrangements in ocular lymphoma.

BACKGROUND: The morphologic diagnosis of primary and metastatic intraocular lymphoma (IOL) was made difficult by the paucicellular specimens with fragile populations of lymphocytes retrieved through pars plana vitrectomy (PPV). The analysis of immunoglobulin heavy chain (IgH) gene rearrangements (AIGHR) was used as an adjunct to cytopathology and flow cytometry in systemic lymphoma. In IOL, the sensitivity and specificity of AIGHR are unknown. METHODS: The authors reviewed the clinical records of patients who underwent PPV for suspicion of IOL at the Immunology and Uveitis Service of the Massachusetts Eye and Ear Infirmary (Boston, MA) between 2000 and 2002. AIGHR was performed as a routine diagnostic test on cell lysates isolated from < 0.5 mL of vitreous fluid. The authors used seminested polymerase chain reaction (PCR) with consensus primers for the VDJ-region of the IgH gene. PCR products were analyzed by polyacrylamide gel electrophoresis. RESULTS: Thirty patients (37 specimens) with chronic vitritis and 17 patients (23 specimens) with IOL were included. The specificity of vitreous fluid cytopathology, flow cytometry, and AIGHR was 1.0, and the sensitivity values were 0.24, 0.36, and 0.64, respectively. AIGHR was negative in two patients for whom cytopathology or flow cytometry revealed the diagnosis of lymphoma. Clonal IGHR was found in four specimens classified as negative for lymphoma based on cytopathology and flow cytometry. CONCLUSIONS: AIGHR supplemented cytopathology and flow cytometry to increase the diagnostic yield in IOL.

Adolescent↗
PubMed2005

An update on oligodendroglial neoplasms.

PURPOSE OF REVIEW: The most widely accepted brain tumor classification system remains morphology-based but the increasing knowledge of the molecular pathogenesis of oligodendroglial tumors has spurred translational research yielding new diagnostic and therapeutic paradigms. These data have accumulated rapidly and, in combination with exciting new insights in the cellular origin of these tumors, necessitate a review. RECENT FINDINGS: 'Cancer stem cells' have been identified in gliomas. Further study of these cells will not only provide information on the cellular origin and pathogenesis of these tumors but may also give rise to new treatments that target a cell pool not amenable to current therapeutic strategies. Molecular tumor characteristics have been correlated with imaging findings, treatment response and prognosis. This has enabled neuro-oncologists to take a risk-stratified approach to patients with oligodendrogliomas that optimizes treatment efficacy and minimizes toxicity. Furthermore, more accurate epidemiological data have become available from population-based studies. SUMMARY: In spite of remarkable progress over the last 15 years, these tumors remain incurable. The search for a cure has to go on, while currently available multidisciplinary treatments are refined.

Brain Neoplasms↗