Klaus Kuchelmeister

Chordoid Glioma of the Third Ventricle: Immunohistochemical and Molecular Genetic Characterization of a Novel Tumor Entity

Chordoid glioma of the third ventricle was recently reported as a novel tumor entity of the central nervous system with characteristic clinical and histopathological features (Brat et al., J Neuropathol Exp Neurol 57: 283–290, 1998). Here, we report on a histopathological, immunohistochemical and molecular genetic analysis of five cases of this rare neoplasm. All tumors were immunohistochemically investigated for the expression of various differentiation antigens, the proliferation marker Ki‐67, and a panel of selected proto‐oncogene and tumor suppressor gene products. These studies revealed a strong expression of GFAP, vimentin, and CD34. In addition, most tumors contained small fractions of neoplastic cells immunoreactive for epithelial membrane antigen, S‐100 protein, or cytokeratins. The percentage of Ki‐67 positive cells was generally low (< 5%). All tumors showed immunoreactivity for the epidermal growth factor receptor and schwan‐nomin/merlin. There was no nuclear accumulation of the p53, p21 (Waf‐1) and Mdm2 proteins. To examine genomic alterations associated with the development of chordoid gliomas, we screened 4 tumors by comparative genomic hybridization (CGH) analysis. No chromosomal imbalances were detected. More focussed molecular genetic analyses revealed neither aberrations of the TP53 and CDKN2A tumor suppressor genes nor amplification of the EGFR, CDK4, and M DM2 proto‐oncogenes. Our data strongly support the hypothesis that chordoid glioma of the third ventricle constitutes a novel tumor entity characterized by distinct morphological and immunohistochemical features, as well as a lack of chromosomal and genetic alterations commonly found in other types of gliomas or in meningiomas.

Expression of the high-affinity choline transporter CHT1 in rat and human arteries.

The arterial vascular wall contains a non-neuronal intrinsic cholinergic system. The rate-limiting step in acetylcholine (ACh) synthesis is choline uptake. A high-affinity choline transporter, CHT1, has recently been cloned from neural tissue and has been identified in epithelial cholinergic cells. Here we investigated its presence in rat and human arteries and in primary cell cultures of rat vascular cells (endothelial cells, smooth muscle cells, fibro-blasts). CHT1-mRNA was detected in the arterial wall and in all isolated cell types by RT-PCR using five different CHT1-specific primer pairs. Antisera raised against amino acids 29–40 of the rat sequence labeled a single band (50 kD) in Western blots of rat aorta, and an additional higher molecular weight band appeared in the hippocampus. Immunohistochemistry demonstrated CHT1 immunoreactivity in endothelial and smooth muscle cells in situ and in all cultured cell types. A high-affinity [3H]-choline uptake mechanism sharing characteristics with neuronal high-affinity choline uptake, i.e., sensitivity to hemicholinium-3 and dependence on sodium, was demonstrated in rat thoracic aortic segments by microimager autoradiography. Expression of the high-affinity choline transporter CHT1 is a novel component of the intrinsic non-neuronal cholinergic system of the arterial vascular wall, predominantly in the intimal and medial layers.

Association of homozygous LMNA mutation R471C with new phenotype: Mandibuloacral dysplasia, progeria, and rigid spine muscular dystrophy†

We report on a 7‐year‐old girl with a phenotype combining mandibuloacral dysplasia (MAD), progeria, and rigid spine muscular dystrophy. Mild proximal weakness, contractures, and rigidity of the spine were the primary findings. Although present since birth, dysmorphic manifestations typical for MAD and progeroid features became more prominent with time, and the full clinical phenotype was recognizable at early school age. Her phenotype was caused by a homozygous mutation in LMNA (c.1411C > T, which predicts p.R471C) inherited from the heterozygous, consanguineous, unaffected parents. This mutation has only been reported in compound heterozygous state and was associated with a milder phenotype. Some LMNA mutations are known to cause MAD and overlapping phenotypes (MAD spectrum) in an autosomal recessive pattern. The p.R471C homozygous LMNA mutation causes a severe phenotype of the MAD spectrum. This case extends the clinical spectrum of MAD and further expands the phenotypic range of lamin A/C associated diseases.

A new model of reversible sinus sagittalis superior thrombosis in the rat: magnetic resonance imaging changes.

OBJECTIVE: The causes of cerebral sinus and vein occlusion and the accompanying parenchymal changes remain largely unexplained. The clinical variability and low incidence of the disease complicate systematic clinical investigations. Animal studies are indispensable; however, existing animal models of sinus thrombosis do not allow for long-term follow-up studies and are not suitable for pharmacological recanalization because sinus thrombosis is induced by ligation and injection of thrombogenic substances and does not resemble sinus thrombosis in humans. METHODS: We induced thrombosis of the superior sagittal sinus (SSS) by careful topical application of ferric chloride onto the SSS of rats, leading to highly reproducible occlusions. Magnetic resonance imaging was performed immediately after initiation of thrombosis and on postoperative Days 1, 2, and 7. Diffusion- and T2-weighted images allowed for calculation of the apparent diffusion coefficient and T2 relaxation time. Vascular status was assessed by venous magnetic resonance angiography. Neurological deficits were assessed with the rotarod test. RESULTS: Seven days after induction of thrombosis, partial recanalization (50.7% of the SSS remaining occluded) was accompanied by a resolution of early generalized changes of the apparent diffusion coefficient and of T2 relaxation time, indicating edema of the entire brain parenchyma. Compared with sham-treated animals, clinical skills in the experimental group improved over time, which was statistically independent from the degree of recanalization. Histopathological analysis revealed no signs of cerebral infarction. CONCLUSION: This is the first animal model of SSS thrombosis that offers the possibility to investigate pathophysiological aspects of the disease as well as the influence of therapy on the nature of disease progression.

Clonal analysis in glioblastoma with epithelial differentiation

Epithelial differentiation in glioblastomas (GBM) may be associated with circumscribed growth and focal keratin expression resembling carcinoma metastasis. Therefore these rare lesions can pose a diagnostic problem suggesting coincidental occurrence of two separate neoplasms. However molecular analysis should succeed in establishing a common origin of seemingly unrelated tumor samples. Five GBMs exhibiting epithelial differentiation were microdissected and analyzed for mutations in the TP53 gene. SSCP analysis of exons 5–8 was followed by direct sequencing of aberrantly migrating fragments. TP53 mutations were identified in tumors from two of five patients. A G → T transversion in codon 176 was detected in a tumor, initially diagnosed as metastases of unknown origin, however, a later autopsy revealed GBM. In this lesion, the mutation was observed in both, areas of astrocytic differentiation and areas of epithelial differentiation. One tumor diagnosed as GBM with epithelial differentiation carried C→T transition in codon 211 in both, areas of astrocytic and epithelial differentiation. Thus, molecular analysis proved clonality in two GBMs with epithelial differentiation, thereby excluding a collision tumor. The present data support the concept of clonal origin of these morphologically heterogeneous lesions.

[Spinal and cerebral leptomeningeal seeding from a melanocytoma of the cerebello-pontine angle]

Die meningeale Tumoraussaat ist eine seltene klinische Manifestation des primar gutartigen leptomeningealen Melanozytoms. Spinale Metastasen des Melanozytoms wurden bisher nur als Kasuistiken beschrieben. Wir berichten uber den klinisch zweiphasigen Verlauf dieses melanozytaren Tumors mit einer zunachst stabilen Phase und nachfolgender rascher Progedienz. Nach Resektion des Primartumors im Bereich des linken Felsenbeins konnte ein Lokalrezidiv nach 5 Jahren wieder in toto entfernt werden. 6 Jahre nach der Erstdiagnose trat ein erneutes lokales Rezidiv mit zerebraler und spinaler meningealer Aussaat auf, woran der Patient trotz kombinierter Radiochemotherapie mit der Gabe von Temozolomid funf Monate spater verstarb. Der rasch progrediente Verlauf des zweiten Rezidivs lasst auf eine sekundare Malignisierung schliesen.

Spinale und zerebrale Meningeosis eines sekundär malignisierten Melanozytoms des Kleinhirnbrückenwinkels

Die meningeale Tumoraussaat ist eine seltene klinische Manifestation des primar gutartigen leptomeningealen Melanozytoms. Spinale Metastasen des Melanozytoms wurden bisher nur als Kasuistiken beschrieben. Wir berichten uber den klinisch zweiphasigen Verlauf dieses melanozytaren Tumors mit einer zunachst stabilen Phase und nachfolgender rascher Progedienz. Nach Resektion des Primartumors im Bereich des linken Felsenbeins konnte ein Lokalrezidiv nach 5 Jahren wieder in toto entfernt werden. 6 Jahre nach der Erstdiagnose trat ein erneutes lokales Rezidiv mit zerebraler und spinaler meningealer Aussaat auf, woran der Patient trotz kombinierter Radiochemotherapie mit der Gabe von Temozolomid funf Monate spater verstarb. Der rasch progrediente Verlauf des zweiten Rezidivs lasst auf eine sekundare Malignisierung schliesen.

APRIL 2004: WOMAN IN HER EARLY FIFTIES WITH A CERVICAL INTRASPINAL AND EXTRASPINAL MASSLESION

April 2004: A 53‐year‐old woman presented with a large club‐shaped intra‐ and extraspinal tumor of the C6 nerve root which had intradurally grown through the enlarged C5–6 neural foramen and focally infiltrated the dura mater. Microscopy revealed a melanin‐pigmented tumor with spindle‐shaped and epithelioid cells and scattered psammoma bodies, a so‐called psammomatous melanotic schwannoma (PMS). More than half of the patients with PMS have Carney complex, a genetically heterogeneous multiple neoplasia syndrome of autosomal‐dominant inheritance, which in our patient, however, could not be detected unequivocally. Prognosis of all melanotic schwannomas (MSs) is not good with local recurrences or metastases in over 40% of cases. In our case, frequent versicular nuclei with distinct nucleoli, occasional mitoses and apoptoses and increased focal MIB‐1 labeling indices prompted us to diagnose a malignant PMS. However, histologic criteria for malignancy in MSs are not clearly defined and there is no reliable histopathological indicator of malignant clinical behavior in MSs. Therefore, designation of “PMS with malignant histologic features” may be more appropriate. Since tumor recurrences and metastases im MSs may occur after more than 5 years, long‐term follow‐up of affected patients is required. One year after operation our patient showed no signs of tumor recurrence or metastases.

Spinal and cerebral leptomeningeal seeding from a melanocytoma of the cerebello-pontine angle@@@Spinale und zerebrale Meningeosis eines sekundär malignisierten Melanozytoms des Kleinhirnbrückenwinkels

Die meningeale Tumoraussaat ist eine seltene klinische Manifestation des primar gutartigen leptomeningealen Melanozytoms. Spinale Metastasen des Melanozytoms wurden bisher nur als Kasuistiken beschrieben. Wir berichten uber den klinisch zweiphasigen Verlauf dieses melanozytaren Tumors mit einer zunachst stabilen Phase und nachfolgender rascher Progedienz. Nach Resektion des Primartumors im Bereich des linken Felsenbeins konnte ein Lokalrezidiv nach 5 Jahren wieder in toto entfernt werden. 6 Jahre nach der Erstdiagnose trat ein erneutes lokales Rezidiv mit zerebraler und spinaler meningealer Aussaat auf, woran der Patient trotz kombinierter Radiochemotherapie mit der Gabe von Temozolomid funf Monate spater verstarb. Der rasch progrediente Verlauf des zweiten Rezidivs lasst auf eine sekundare Malignisierung schliesen.