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 Achúcarro-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...

We report a 69-year-old woman of Mexican origin with a 6-year history of progressive paresis, mild peripheral neuropathy, and recent onset of fluctuating mental status. Head and spinal MRI revealed contrast enhancing thickened meninges which on biopsy disclosed amyloid deposition. Immunohistochemistry identified the amyloid as transthyretin (TTR), and polymerase chain reaction/restriction fragment length polymorphism analysis of blood revealed a Val30Met mutation in one of her TTR genes. This mutation causes familial (hereditary) amyloidotic polyneuropathy of the Portuguese type (FAP 1). However, unlike FAP 1, in which peripheral neuropathy is a dominant feature, our patient's clinical manifestations, which included communicating hydrocephalus and myelopathy, were more suggestive of familial oculoleptomeningeal amyloidosis (FOLMA). In summary, the clinical presentation of TTR Met 30 mutation is more varied than previously suspected, and leptomeningeal amyloidosis should be considered in the differential diagnosis of obscure conditions involving meninges.

We describe 5 individuals (from three separate families) with a progressive neurological disorder characterized by sensorimotor peripheral polyneuropathy, cranial neuropathies (external ophthalmoplegia, deafness), and the syndrome of chronic intestinal pseudo-obstruction. Magnetic resonance imaging showed widespread abnormality of the cerebral and cerebellar white matter in the 2 patients studied. Autopsy examination in 3 revealed widespread endoneurial fibrosis and demyelination in the peripheral nervous system, possibly secondary to axonal atrophy, and poorly defined changes in cerebral white matter (leukoencephalopathy). The cranial nerves and spinal roots were less severely involved and the neurons in the brainstem and spinal cord were intact. The fatal gastrointestinal dysmotility was due to a severe visceral neuropathy. We suggest that these patients manifested a hereditary disorder with distinctive clinical, radiological, and neuropathological features, and propose the acronym POLIP to emphasize the distinctive tetrad of polyneuropathy, ophthalmoplegia, leukoencephalopathy, and intestinal pseudo-obstruction.

Ectopic pituitary adenomas should be considered in the differential diagnosis for all patients with Cushing's syndrome. Furthermore, surgical approaches should be chosen carefully once the diagnosis of ectopic pituitary adenoma is made.