Matrix gene expression analysis and cellular phenotyping in chordoma reveals focal differentiation pattern of neoplastic cells mimicking nucleus pulposus development.

Chordoma is the fourth most common malignant primary neoplasm of the skeleton and almost the only one showing a real epithelial phenotype. Besides classic chordoma, so-called chondroid chordoma was described as a specific entity showing cartilage-like tissue within chordomatoid structures. However, since its first description, strongly conflicting results have been reported about the existence of chondroid chordoma and several studies suggested chondroid chordomas being in fact low-grade conventional chondrosarcomas. In the present study, we used cytoprotein expression profiling and molecular in situ localization techniques of marker gene products indicative of developmental phenotypes of chondrocytes to elucidate origin and biology of chondroid chordoma. We were able to demonstrate the chondrogenic potential of chordomas irrespectively of the appearance of overt cartilage formation by identifying the multifocal expression of type II collagen, the main marker of chondrocytic differentiation. Additionally, the cartilage-typical large aggregating proteoglycan aggrecan was present throughout all chordomas and, thus, a very characteristic gene product and marker of these neoplasms. Biochemical matrix composition and cell differentiation pattern analysis showed a high resemblance of classic chordomas and in chordoid areas of chondroid chordomas to the fetal chorda dorsalis, whereas chondroid areas of chondroid chordomas showed features similar to adult nucleus pulposus. This demonstrates on the cell function level the chondrocytic differentiation potential of neoplastic chordoid cells as a characteristic facet of chordomas, mimicking fetal vertebral development, ie, the transition of the chorda dorsalis to the nucleus pulposus. Our study firmly establishes a focal real chondrocytic phenotype of neoplastic cells in chordomas. Chondroid chordoma is neither a low-grade chondrosarcoma nor a misnomer as discussed previously.

Meningovascular neurosyphilis in human immunodeficiency virus infection as a differential diagnosis of focal CNS lesions: a clinicopathological study.

The acquired immunodeficiency syndrome (AIDS) appears to alter the course of syphilis and particularly neurosyphilis. We report the case of an HIV-positive patient with two CNS lesions due to vascular complications of neurosyphilis of the meningovascular type, 18 months after he had developed a penile chancre. On admission, CT scans were inconsistent with cerebral toxoplasmosis or CNS lymphoma. At necropsy, histopathological examination showed typical Heubner's endarteritis of the basilar and posterior cerebral arteries. In AIDS patients, superadded meningovascular syphilis must be suspected, especially when CT scanning reveals the presence of multi-focal, low density lesions with the particular characteristics of infarction.

Studies in polycythemia after kidney transplantation.

Mononuclear cells from peripheral blood of six patients with polycythemia after kidney transplantation were studied in methyl cellulose cultures using fetal calf serum with and without adding erythropoietin. Parallel tests were run with "synthetic medium". The data obtained were compared to those of patients with polycythemia vera and normal subjects. The erythropoietin independent proliferation in synthetic medium typical for polycythemia vera could not be found in patients with renal grafts. However, in the preparations with fetal calf serum without erythropoietin, a formation of erythroid colonies could be detected suggesting an increased sensitivity or proliferation of erythropoietically determined stem cells in patients with transplanted kidneys.

[Wallenberg's syndrome (author's transl)]. / Das Wallenberg-Syndrom. Eine typische Komplikation der Hypertonie.

Wallenberg's syndrome includes a series of symptoms caused by obliteration of small arteries supplying the medulla oblongata. In the differential diagnosis it must be separated from lesions of the pons. Cause of the arterial block was first considered to be an embolus, inflammatory processes were later also incriminated. The course of the disease and autopsy findings in a 57-year-old man who had arterial hypertension for 20 years show that Wallenberg's syndrome can be a typical complication of chronic hypertension.