Primary intraosseous meningioma: case report

Summary A case of 72-year-old Japanese woman with a rare intraosseous meningioma is presented. The tumor was located in the right frontoparietal region, involving the coronal suture. The tumor was excised totally and the pathological diagnosis was meningioma. Similar cases reported in the past literature are reviewed and the possible histogenetic mechanism of the tumor is discussed.     

Self-assembly of cortical plate cells in vitro within embronic mouse cerebral aggregates. Golgi and electron microscopic analysis

Mouse isocortical cells were dissociated at 18 days of embryonic development and were reaggregated in vitro by rotation in a gyratory incubator shaker. The internal organization of the resulting aggregates was studied by conventional light microscopy, Golgi impregnation, and electron microscopy, establishing the following pattern of reasembly: (1) the predominant cell type in the aggregates was the pyramidal neuron; (2) each of these pyramidal neurons tended to orient its apical dendrite toward the surface of the aggregate; and (3) in larger aggregates (diameter 600 μm) there was prominent parallel alignment of pyramidal cell apical dendrites. These characteristics resulted in an in vitro reconstruction of the major features of isocortex observed in situ, including formation of a superficial, rather acellular plexiform layer. Reconstruction of isocortical architecture appeared to take place independently of either a germinal epithelium, a radiaal glial framework, or an outer mesenchymal scaffold. Analysis of the events occurring during aggregate formation suggests that intrinsic cellular information accounts for the expression of basic pyramidal cell morphology. However, dendritic orientation and alignment are most likely determined by cell-cell interactions dependent upon specific cell surface recognition properties, as well as by geometric restraints imposed by the spherical or cylindrical shape of the aggregates.     

Development and differentiation of early generated cells of sublayer VIb in the somatosensory cortex of the rat: a correlated Golgi and autoradiographic study

Autoradiographic and Golgi techniques are used to study the origin, developmental characteristics, and adult morphology of the cells of sublayer VIb in the somatosensory cortex of the rat. In the adult rat, this sublayer forms a stratum of two to three rows of cells located immediately above the white matter. It is clearly separated from the remaining cortical layers by a light plexus of fibers. The cortical plate begins to appear in the lateral wall of the brain hemisphere at embryonic day 15 (E15). By using tritiated thymidine autoradiography, we can see that cells generated between E12 and E14 become located in layers I, V, and VI in the adult. After injections on E12, heavily labeled cells were found almost exclusively in layer I and in sublayer VIb, indicating that these are the earliest generated cells in the neocortex of the rat. No labeled cells were found in sublayer VIb after injection on E15. We describe the morphology of cells of layer VI from E15 to the adult using the Golgi technique. Our observations show the existence of different types of cells, among which we found horizontal bipolar cells very early during development. They transform into horizontal and inverted pyramidal cells, which are the predominant morphological types found in the adult. Horizontal cells lie at the lower part of sublayer VIb. Inverted pyramidal cells have descending apical dendrites penetrating the white matter. Their axons form ascending loops turning into projection fibers. A correlation with previous studies and some functional implications indicating the unique role of sublayer VIb in the rat during development and in the adult are discussed.     

Rhabdoid tumour of the bladder: a histological, ultrastructural and immunohistochemical study

A rapidly fatal bladder tumour which had the features of a rhabdoid tumour was studied by sequential biopsies and at autopsy. This is the first rhabdoid tumour recorded at this site and the first in which there was co-existent transitional cell carcinoma. The possibility that rhabdoid tumour is histogenetically heterogeneous is discussed.     

Glandular lesions of the urinary bladder:clinical significance and differential diagnosis

Williamson S R, Lopez‐Beltran A, Montironi R & Cheng L
(2011) Histopathology  58 , 811–834
Glandular lesions of the urinary bladder: clinical significance and differential diagnosis A variety of glandular or pseudoglandular lesions may be seen in the urinary bladder, ranging from those that are entirely benign to aggressive‐behaving malignant primary and secondary tumours. Lesions with minimal to no evident premalignant potential include several proliferative and reactive processes, such as cystitis cystica and cystitis glandularis, although the possibility exists for confusion of such lesions with an infiltrative neoplasm, particularly in limited biopsy specimens. Similarly, ectopic tissues of Müllerian origin may be seen occasionally in the urinary bladder and their differentiation from a true glandular neoplasm is important to avoid improper treatment. As urothelial carcinoma has a propensity for divergent differentiation, a wide spectrum of morphological variants exists with varying degrees of glandular differentiation. Some such variants have demonstrated clinical behaviour that is more aggressive than their histology would suggest, thus deserving recognition and potentially different treatment. In this paper, we review the glandular lesions of the urinary bladder ranging from benign proliferative processes to malignant primary and secondary neoplasms, with emphasis on clinical significance and features useful in resolving their differential diagnoses.     

Microcystic meningioma: Clinicopathological features of 6 cases

Abstract

The clinical and morphological features of 6 patients with unusual meningiomas with extensive microcystic formation are presented. There were 4 males and 2 females, ranging in age from 30 to 64 years. The clinical and neuro-imaging features of these tumours were identical with those of meningiomas in general. Morphological examinations disclosed that the tumour cells in 4 cases had many ultrastructural characteristics in common with the arachnoid cap cells, viz. prominent and complex interdigitation of the fine cytoplasmic processes, many desmosomes, and intracytoplasmic microfilaments. In contrast, the tumour cells of 2 cases had characteristic structures in common with trabecular arachnoid cells, viz. stellate in shape, a small number of intracytoplasmic filaments, relatively thick cytoplasmic processes, and occasional desmosomes. The tumour cells in these 2 cases were considered to recapitulate the subarachnoid structure and showed microcystic appearance. Although the histogenesis of microcysts in meningiomas is considered not to be uniform, the biological behaviour of these 6 tumours corresponded to those of meningiomas in general. [Neurol Res 1994; 16: 251-256]     

Structural-functional reorganization of nonapeptidergic neurosecretory hypothalamic nuclei in experimental acute pancreatitis

Structures of the pancreas and magnocellular (supraoptic and paraventricular) nuclei of the hypothalamus of adult male rats were studied in conditions of acute pancreatitis at the light and electron microscopic levels. Histo-and organotypic changes in the parenchymatous and stromal elements of the pancreas were analyzed simultaneously with cytological assessment of the state of the nonapeptidergic neurosecretory centers of the hypothalamus. Blockade of the release of hypothalamic nonapeptides was found to occur at the level of axovasal complexes, and this aggravated the outcome of destructive and necrobiotic changes in the pathologically altered organ. __________ Translated from Morfologiya, Vol. 128, No. 5, pp. 37–40, September–October, 2005.     

Cytokeratin 20-positive large cell neuroendocrine carcinoma of the colon

Herein is presented a case of cytokeratin (CK) 20-positive large cell neuroendocrine carcinoma of the colon, in which the tumor was clinically at stage IV and located in the ascending colon. Pathological examination of the resected tumor revealed nested and solid proliferation of large undifferentiated cells with vesicular nucleus and prominent nucleoli. No areas showed differentiation toward adenocarcinoma or squamous cell carcinoma. Tumor cells were immunohistochemically positive for chromogranin A, synaptophysin, CD 56 (focal), and bore electron-dense granules. With these features, the tumor was diagnosed as a large cell neuroendocrine carcinoma of the colon. Liver metastasis and local recurrence progressed, and the patient died of the primary disease 7 months after operation. The autopsy confirmed this diagnosis without detectable tumors in the lungs. Interestingly, more than half of the tumor cells were positive for CK 20, while CK 7 was not expressed. Most neuroendocrine carcinomas do not express CK 20, with the exception of Merkel cell carcinomas, and most colorectal adenocarcinomas express CK 20. To the best of the authors' knowledge, the present case is the first CK 20-positive, CK 7-negative colorectal neuroendocrine carcinoma to be described, suggesting a link between colorectal neuroendocrine carcinoma and conventional adenocarcinoma.