1/6. Neuroradiological characteristics of pineocytoma and pineoblastoma.We reviewed neuroradiological images in two histologically proven cases of pineocytoma and three of pineoblastoma to delineate the characteristic features of these rare tumours. CT revealed isodense or slightly hyperdense masses with central or peripheral calcification; enhancement with contrast medium tended to be homogeneous in pineocytomas and heterogeneous in pineoblastomas. In the pineocytomas, T1-weighted images revealed rounded, sometimes or slightly lobulated low-signal masses with strong, homogeneous contrast enhancement. Their margin was clear, without invasion of adjacent structures. In the pineoblastomas, however, T1-weighted images revealed multilobulated tumours with heterogeneous contrast enhancement. All three pineoblastomas had poorly defined margins with adjacent structures such as the posterior thalamus or corpus callosum, suggesting a more invasive nature. T2-weighted images revealed nonspecific high signal lesions in all five cases.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
2/6. Peduncular hallucinosis due to a pineal meningioma. Case report.The authors report the case of a 53-year-old woman who experienced visual hallucinations diagnosed as peduncular hallucinosis (PH). The cause of the PH was compression of the quadrigeminal plate and/or the splenium due to a meningioma originating from the falcotentorial junction (pineal meningioma). The nature of the visual hallucinations was depicted in drawings created by the patient herself. This is the first report of PH caused by a tumor located in the pineal region.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
3/6. Papillary neuroepithelial tumor of the pineal region. A case report.We present here an unusual case of papillary neuroepithelial tumor of the pineal region. The patient was a 29-year-old female who presented with headaches. A computed tomography scan revealed a tumorous lesion at the pineal region and hydrocephalus. The resected tumor was composed of columnar and cuboidal cells showing characteristics of papillary growth. The tumor cells exhibited diffuse and intense immunoreactivity to cytokeratins and neural cell adhesion molecule. The tumor expressed abundant levels of transthyretin (prealbumin) and appeared ependymal in nature, with numerous microlumens delineated by punctate and ring-like patterns in epithelial membrane antigen staining. Reactivity to synaptophysin and glial fibrillary acidic protein was observed only in the infiltrated non-neoplastic pineal parenchyma. These histological characteristics matched the description of the recently reported papillary tumor of the pineal region thought to originate from the specialized ependyma of the subcommissural organ (SCO). Transthyretin expression of the present case further supports the likelihood of SCO origin, as transthyretin is one of the proteins presumed to be secreted by human SCO.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
4/6. cytogenetics of pineoblastoma: four new cases and a literature review.Pineoblastoma represents a class of primitive neuroectodermal tumors (PNET) with poorly differentiated neuroepithelial cells that are histologically indistinguishable from medulloblastomas. It is a rare tumor, typically arising in childhood, and to date only a few cytogenetic cases have been published. We report four new cases in which conventional cytogenetics demonstrated the presence of an abnormal clone. The tumors showed a variety of ploidy levels, from hypodiploid to hypertetraploid. Both structural and numerical aberrations were frequent, and in three out of the four cases a large degree of cell-to-cell variation was observed. The most frequently involved chromosome in structural rearrangements was chromosome 1, observed in three of the four cases. The short arm was involved in two of the three cases; in the third case, the anomaly was in the long arm. Two cases showed unbalanced gain of chromosome 17q, one of them showing i(17)(q10). Together, the four cases illustrate the complex karyotypic nature of this tumor type and represent a step toward determining whether a nonrandom cytogenetic picture exists and how this may be related to other associated tumor types.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
5/6. The cytological differentiating potential of pineal parenchymal neoplasms (true pinealomas). A clinicopathological study of 28 tumours.A series of 28 pineal parenchymal tumours is described, with special reference to the potential of some of these neoplasms to differentiate along glial or ganglionic lines, or both. The more undifferentiated tumours (pineoblastomas, 11 cases) were the most frequent: they are histologically similar to medulloblastomas. One example showed focal differentiation to retinoblastoma at the primary site. The histological features of pineoblastomas merged with those of pineocytomas (7 cases), in which the lobular architecture is reminiscent of that of the mature pineal gland. In addition, 10 further examples in the group of pineocytomas showed more advanced differentiation as follows: towards astrocytes only (2 cases), towards ganglion cells only (1) case) and towards both astrocytes and ganglion cells (gangliogliomas) (7 cases). Confirmation of the pineal parenchymal nature of these neoplasms and of their differentiating potential was provided by a modification of the Achucarro-Hortega's silver carbonate impregnation technique for pineal parenchymal cells, by specific silver impregnations for axonal processes, and by an immunoperoxidase stain for glial fibrillary acidic (GFA) protein. Electron microscopy of one new example of pineocytoma with neuronal and astrocytic differentiation demonstrated the presence of numerous microtubules, of clear-centred and dense-core vesicles, and of synaptic complexes. Seven illustrative clinical histories with pathological findings are presented. The identification of special features of cellular differentiation is of importance in evaluating the biological behaviour of these neoplasms since a definite correlation can be established between the patient's age, some of the cytological variants, and the malignant potential of the tumour. Pineoblastomas are highly malignant neoplasms of children and young adults which disseminate widely throughout the cerebrospinal fluid pathways. -ineocytomas without cellular evidence of further differentiation occur at any age and are also clinically malignant, but with a somewhat lesser tendency to metastasize than pineoblastomas. Pineobytomas with astrocytic differentiation occur in adults and may be either slowly growing or malignant. Pineocytomas with neuronal or with neuronal and astrocytic differentiation occur in later life, remain localized, and are relatively benign. Since the latter account for approximately one-third of pineal parenchymal tumours and are likely to be relatively radio-resistant, tissue diagnosis is imperative for a determination of the therapeutic approach. radiation to the entire neuraxis should be administered to patients with pineoblastomas and malignant pineocytomas in view of their high frequency of cerebrospinal metastasis. An accurate histological classification of these tumours therefore carries important clinical and therapeutic implications...- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
6/6. Virus-like particles in human pinealoma.Virus-like particles were seen in the tumour cells of a pinealoma in a male of 18 years. The particles were dense, spherical or hexagonal in shape, and 100-130 nm in size. They were found in the cytoplasm, but not in the nucleus. They occurred in aggregates or in isolation. They tended to form rows or circles. These particles may be viral in nature, and of one of the herpes-, leuro- or arena-groups, especially when judged from their size. However, greater certainty as to their nature is impossible from the morphological evidence.- - - - - - - - - - ranking = 2keywords = nature (Clic here for more details about this article) |