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[Arteries of the thalamus in man. Choroidal arteries. III. Absence of the constituted thalamic territory of the anterior choroidal artery. IV. Arteries and thalamic territories of the choroidal and postero-median thalamic arterial system. V. Arteries and thalamic territories of the choroidal and postero-lateral thalamic arterial system].

The anterior chor oideal artery cannot be considered as an arterial source for thalamic vascularization. Its territory is primarily pallidocapsular and reaches the thalamus only irregularly and superfically. 2. The posteromedian choroideal and thalamic system, in its infrathalamic portion, gives off lateral mesencephalosubthalamic, inferocentral (for the tips of the arcuate nucleus and the inferolateral part of the centre median nucleus), brachiopulvinarian and posterocentral arteries. In its suprathalamic portion it gives off medial pulvinarian and superomedian thalamic arteries. These arteries irriguate the major part of nucleus medialis and the nucleus anterior. 3. The posterolateral choroideal and thalamic system gives off lateral genicular arteries (for the lateral geniculate body), inferolateral pulvinarian and superolateral thalamic arteries. These arteries irriguate the dorsal part of the interal region of the thalamus.

Arteries

The choroid plexus of the mature and aging rat: the choroidal epithelium.

The choroid plexus of mature and old rats has been examined by both scanning and transmission electron microscopy. It has been shown that the macrophages lying upon the ventricular surface of the choroid plexus have a close association with burr-like protrusions that extend from the apical surfaces of the choroidal epithelial cells. These protrusions have a dark cytoplasm filled with vesicles and tubules, and projecting from them are thin, shrunken microvilli. It is suggested that these protrusions are phagocytosed by the macrophages and that they are the source of some of the inclusions which become increasingly common within the cytoplasm of macrophages in older rats. The lateral surfaces of the choroidal epithelial cells have also been examined in the scanning electron microscope after exposure of the surfaces by dissection. In such preparations it is apparent that the elaborate interdigitations between adjacent cells are effected by irregular and vertically arranged folds confined to the basal portions of the lateral cell surfaces. Lastly, it has been shown that at the junction between the choroid plexus and the ependyma in the lateral ventricle, there are two modes of transition between the choroidal and ependymal epithelia. In one, typical choroidal and ependymal epithelial cells lie next to each other to produce a distinct and continuous bondary. In the other mode the boundary is also continuous, but there are modified ependymal cells present. These modified cells have short, relatively sparsely distributed microvilli and not more than one or two cilia.

Aging

The hypothalamo-choroidal tract. I. Immunohistochemical demonstration of neurophysin pathways to telencephalic choroid plexuses and cerebrospinal fluid.

Neurosecretory pathways were examined in normal male rats by the use of the immunoperoxidase technique for the localization of neurophysin in Bouin-fixed, deparaffinized sections. Using this technique two projections of extrahypothalamic neuorosecretory fibers can be traced to the sites of origin of the choid plexuses of both horns of the lateral ventricles. Neurophysin-containing axons originating primarily from the paraventricular field course dorsolaterad to enter the choroid fissure of the dorsal horn. A caudally direced group of fibers course ventrolaterad to enter the ventral horn choroid fissures. The supraoptic nuclear field is the primary contributor to the latter group. Scattered neurosecretory neurons are found in association with both pathways, usually in contact with blood vessels supplying the choroid plexuses, or in the telencephalic subependymal stroma. Neurosecretory fibers and terminals occur within the choroid fissures and juxtaventricular neuropil. The neurosecretory terminals in the choroid fissures appear as Herring-body type neurohemal organs; in the neuropil they appear as punctate peri-neuronal desities suggestive of synaptic contacts. Thes morphologic findings are discussed in relation to reports indicating the presence of antidiuretic, vasopressin-like activity in cerebrospinal fluid and choroid plexus extraxts together with ultrastructural evidence supportive of vasopressin-mediated transchoroidal cerebrospinal fluid absorption. These results and those of others indicated the possible involvement of the neurosecretory system in the regulation of brain interstitial-ventricular cerebrospinal fluid dynamics.

Animals

Malignant melanoma of the choroid associated with spontaneous expulsive choroidal hemorrhage.

A 79-year-old man initially had a perforated corneal ulcer of his blind right eye. The next day a spontaneous expulsive choroidal hemorrhage occurred just before scheduled enucleation. Histopathologic examination of the enucleated eye revealed a severe necrosis of several posterior ciliary arteries in the expulsive choroidal hemorrhage, as well as a large occult spindle B malignant melanoma of the choroid. The necrosis of the posterior ciliary arteries may have been the cause of the choroidal hemorrhage. The finding of an occult malignant melanoma may be more than a chance occurrence of two unrelated events, inasmuch as both are associated with necrosis of the posterior ciliary arteries.

Aged

Melanosis of the choroid plexus, ependyma, subependymal neuroglia, and dentate and trigeminal motor nuclei: observations on the choroidal and ependymal cilia.

Melanosis of the choroid plexus, ependyma, subependymal neuroglia of the fourth ventricle, and dentate and trigeminal motor nuclei was found in a 50-year-old man who died with cor pulmonale, hypertensive cardiovascular disease, and intracerebral hemorrhage. This case is the first known example of melanosis not associated with neurocutaneous melanosis to involve multiple structures of the brain. Nonenzymatic conversion of lipofuscin into melanin is suggested as the mechanism of the melanosis. Cilia of the choroidal epithelium and ependyma were identified in this case, despite a long delay in postmortem examination. These observations on choroidal epithelium confirm previous reports that the choroid plexus of man is ciliated, as in other mammals and lower vertebrates.

Brain Diseases, Metabolic

Osseous choristoma of the choroid simulating a choroidal melanoma. Association with a positive 32P test.

We report the clinical and histopathologic features of an osseous choristoma of the choroid that appeared in a 26-year-old woman. Her diagnostic evaluation included a radioactive phosphorus (32P) uptake test, which was 270% positive and led us to believe that the lesion was an atypical malignant melanoma. The extent of true ossification within this tumor, seen microscopically, explains the false-positive uptake of radioactive phosphorus by this benign tumor; it is well known that bone avidly accumulates radioactive phosphorus. We recommend that all "atypical choroidal melanomas" be studied for the presence of bone, with bone-free roentgenograms, ultrasonography, and possibly, computerized tomographic scans before 32P testing or enucleation. This, to our knowledge, is the second histopathologically proved case of an osseous choristoma of the choroid to be reported in the literature.

Adult

Choroidal neovascularization associated with choroidal nevi.

We observed choroidal neovascularization with associated macular detachment in three cases of benign choroidal nevi. Successful obliteration of the neovascular membranes was performed with argon laser photocoagulation with maintenance of good central visual acuity.

Adult

Malignant melanoma of the choroid presenting as choroidal detachment following cataract surgery.

The progression of a monocular nuclear cataract was observed for thirty-two months in an eye which was apparently otherwise normal. Three weeks after uncomplicated cataract surgery the patient presented with an apparent detachment of the choroid which enlarged dramatically within a relatively short time and which was further complicated by a retinal detachment. The subsequent development of rubeosis iridis and increased intraocular pressure suggested some other etiology. Ultrasonography revealed a malignant melanoma which was confirmed following enucleation. Transillumination of all suspected postoperative choroidal detachments is recommended with more definitive examination when indicated.

Aged

The "Knapp-Ronne" type of malignant melanoma of the choroid. A haemangioma-like melanoma with a typical clinical picture. So-called "preretinal malignant choroidal melanoma".

Five cases of a rare type of malignant melanoma of the choroid with a typical clinical and histopathological picture are reported. This tumour is characterized by it location near the optic disk,its early growth through the retina, its structure with bloodless and blood-filled cavernous spaces, and its manifestation by a massive haemorrhage into the vitreous. "Historical" cases are mentioned, showing that this rare tumour, occurring in about 1:250 of malignant melanomas of the choroid, has a Scandinavian tradition. The clinical and histopathological details are discussed.

Aged

Multicentric primary malignant melanomas of the choroid: two separate malignant melanomas of the choroid and two uveal naevi in one eye.

Two completely separate malignant melanomas of the choroid occurred in 1 eye containing 2 additional uveal naevi. Review of the literature disclosed 7 further patients with unilateral multicentric malignant melanomas of the choroid and 11 bilateral multicentric malignant melanomas of the uvea. General aspects of multicentric primary neoplasia are discussed and an interpretation is attempted.

Choroid Neoplasms

[Scintigraphy of the choroid plexus (choroid plexography)].

An increase concentration of pertechnate in the choroid plexus was demonstrated in 21 patients pretreated with tin pyrophosphate injected intravenously 24 hours before the examination. Using this technique, the choroid plexus are seen quite clearly, giving indirectly a picture of the intracerebral ventricles. A dynamic study was carried out in 12 patients, 3 of whom had abnormalities of the cerebrospinal fluid circulation demonstrated by isotope cisternography. The results obtained were characterised by a typical diphasic curve with variations in the pathological cases.

Brain Neoplasms