Granulomatous amebic encephalitis caused by leptomyxid amebae in an HIV-infected patient.

MR images of granulomatous amebic encephalitis caused by leptomyxid amebae in an HIV-infected patient showed both heterogeneous and ring-enhancing hemorrhagic lesions. The brain was diffusely involved, including the brain stem, deep gray matter nuclei, and corticomedullary junction regions of all lobes.

Concurrence of multiple sclerosis and brain tumor: clinical considerations.

We report a patient with multiple sclerosis (MS) who developed an oligodendroglioma 8 years after the initial diagnosis of MS. This is the first description of a neoplasm, suspected initially on brain MRI and subsequently confirmed by brain biopsy, in an MS patient. Our case emphasizes the need to evaluate atypical brain MRI lesions carefully, even in well-established MS patients, as well as to obtain a tissue diagnosis of such lesions whenever possible in order to determine their precise etiology.

Intramedullary gliofibroma: MR, ultrasound, and pathologic correlation.

We describe the clinical, MR, ultrasound, and pathologic findings of an intramedullary gliofibroma. This uncommon primitive tumor is thought to be of mixed glial and mesenchymal origin. Although the majority of tumors described to date have been histologically benign, clinical course has been quite variable. On MRI, the tumor we report was isointense to adjacent spinal cord on T1-weighted imaging and became hyperintense on proton and T2-weighted imaging. Enhancement with gadolinium diethylenetriamine pentaacetic acid was mild and slightly heterogeneous. Intraoperative ultrasound demonstrated widening of the lower thoracic cord. Echo pattern was generally similar to that of adjacent cord. The major differential diagnostic considerations include astrocytoma and ependymoma.

Pineal parenchymal tumors: an ultrastructural study with prognostic implications.

The pineal gland is host to a spectrum of neoplasms. Those considered to be derived from or differentiating toward pineal parenchymal cells are rare. Traditionally, pineal parenchymal tumors (PPTs) have been divided into 3 types: pineocytomas, pineoblastomas, and mixed or transitional tumors. Their characterization has been far from adequate and no firm diagnostic criteria, light microscopic or ultrastructural, have been established. In an attempt to provide more precise prognostic diagnostic criteria, we undertook a detailed ultrastructural analysis of 17 PPTs and found them to exhibit light microscopic and ultrastructural features strikingly similar to those of pineal parenchymal cells in varying stages of development, ranging from undifferentiated primitive neuroepithelial cells to mature pineal parenchymal cells. We endorse classification of PPTs based on a combination of their light microscopic and ultrastructural features. Accordingly, PPTs can be divided into three categories: 1) pinealoblastoma, 2) PPTs of intermediate or mixed differentiation, and 3) pineocytoma, a tumor of mature-appearing pineocytes. In keeping with this classification, our 3 pinealoblastomas behaved as highly malignant tumors. A correlation of morphology and prognosis was less evident between intermediate tumors and pineocytomas, perhaps the result of considerable variation in surgical and other therapies. Evidence of neurosensory differentiation, a feature noted to a varying extent in all but the pineoblastomas, included club-shaped "nerve endings" in 7 tumors, small numbers of dense core granules in 8, clear vesicles in 7, and structures suggestive of synapses in 4. With the exception of 3 undifferentiated PPTs or pinealoblastomas lacking nerve endings, all pineocytomas exhibited some combination of these markers of neuronal specialization. In that the ultrastructural features of these PPTs were more indicative of their aggressiveness than was their degree of light microscopic differentiation or grade, we consider electron microscopy a useful adjunct, not only in diagnosis but also in therapeutic decision-making and prognostication.

Conjunctival lymphoid hyperplasia.

Our patient had uncommon features of conjunctival lymphoid infiltrates, including patient age, bilaterality, and lesion location. We describe his case and discuss the prognosis based on a literature review.

Intraventricular fibroma: MR and pathologic comparison.

This case report describes clinical, surgical, MR, and pathologic findings of an intraventricular fibroma, a rare, benign mesenchymal neoplasm. Relatively isointense with normal brain parenchyma on T1-weighted images, the tumor exhibited hyperintense signal on T2-weighted pulse sequences and enhanced intensely and homogeneously after intravenous administration of gadopentetate dimeglumine. Choroid plexus papilloma/carcinoma, meningioma, ependymoma, and subependymal giant cell astrocytoma should be included in the differential diagnosis.

Intracranial granulocytic sarcoma: CT, MR, and angiography.

Granulocytic sarcoma is a rare, solid tumor composed of immature granulocytes usually found in association with systemic leukemia in younger patients. We present a case of granulocytic sarcoma occurring in an elderly female with no evidence of systemic leukemia. Computed tomography, MR (with and without Gd-DTPA), and angiography showed features commonly found in meningiomas.

Clinicopathologic correlation and pathogenesis of ocular and central nervous system manifestations in Hallervorden-Spatz syndrome.

We have correlated the clinical and histopathologic features of the eyes and central nervous system in a patient with Hallervorden-Spatz syndrome who died at age 11 years. The main ocular findings included degeneration of photoreceptors, marked thinning of the outer nuclear and outer plexiform layers, retinal gliosis, narrowing and obliteration of blood vessels with a perivascular cuffing of pigment cells, and degenerative changes in the retinal pigment epithelial cells with accumulation of melanolipofuscin. The positive findings in the brain included a symmetrical, partially destructive lesion of the globus pallidus, especially in its internal fibers and neurons; in addition, we noted gliosis, widely disseminated axonal spheroidal bodies, which were most numerous in the globus pallidus and pars reticulata, as well as deposits of iron. Our histopathologic findings implicate three possible mechanisms, namely, lipid peroxidation, a deficiency of fatty acid membrane components, and increased cGMP which, either singly or in combination, are responsible for a pathogenesis that is common to the eye and brain in Hallervorden-Spatz syndrome.

Aicardi syndrome. A clinicopathologic case report including electron microscopic observations.

Aicardi syndrome is characterized by infantile spasms, agenesis of the corpus callosum, severe mental retardation, and a characteristic chorioretinopathy with lacunar defects. The authors report on a 2-year-old girl with congenital hydrocephaly who was found unresponsive by the baby-sitter and died shortly thereafter. At autopsy, the histopathologic findings, which were confined to the brain and eyes, were found highly characteristic of AIC. The main abnormalities included agenesis of the corpus callosum, micropolygyria, bilateral papillomas of choroid plexi, bilateral microphthalmia, bilateral hypoplasia of the optic nerves, bilateral colobomas of the juxtapapillaris choroid and optic disc, bilateral total retinal detachment with dysplastic rosettes and chorioretinal lacunae with focal thinning, and atrophy of the retinal pigment epithelium and choroid. A detailed histopathologic study of the ocular findings and the brain anomalies is presented. The results of scanning electron microscopy of the chorioretinal lacunae demonstrated peculiar papillary proliferations of the retinal pigment epithelium in both eyes.

Sudden death in an infant with central nervous system abnormalities.

Some deaths during the first year of life are classified as sudden infant death syndrome (SIDS), the diagnosis of which requires a complete autopsy without adequate explanation for the death. We report a 1-month-old infant whose clinical history was fairly typical for SIDS. Postmortem examination was remarkable in revealing clinically unsuspected central nervous system (CNS) abnormalities, including lobar holoprosencephaly, absence of the olfactory tracts and grooves (arhinencephaly), subependymal gray matter heterotopias, and delayed myelination. Although the CNS findings do not adequately explain the patient's sudden death, this case illustrates the need for a complete autopsy to include careful CNS evaluation, especially in any presumed SIDS death.

Symptomatic neuroepithelial (colloid) cysts of the third ventricle. A unique case report in nontwin brothers.

Colloid cysts are relatively rare benign tumors comprising less than 2% of all intracranial mass lesions. However, since the advent of computed tomography of the head, these tumors are being recognized more frequently, occasionally before their symptomatic presentation. Much controversy remains as to the true cells of origin and pathogenesis of these cysts. Although a neuroepithelial origin has become increasingly accepted, Rathke cleft cysts, ectopic respiratory tissue, and other endodermal sources have been postulated. The first familial occurrence in middle-aged identical twin brothers was cited recently in the literature. Described here are the first reports of symptomatic colloid cysts in two nontwin brothers, lending further support to the potential for genetic expression of neuroepithelial cysts. Also included are preoperative computed axial tomographic images, histopathologic photomicrographs with case descriptions and comparisons, and suggestions to elucidate further the development and presentation of colloid cysts.

Melanocytic schwannoma.

The clinical, histopathologic, immunohistochemical, and electron microscopic findings of two cases of melanocytic schwannoma are reported. One case, which occurred in the parotid gland, is believed to be the first reported in this location. The other case was located in the sacral spinal region. A review of the clinical and pathologic features of 32 previously reported cases is presented. The recurrence rate was 24%. Those tumors that were incompletely excised and/or located in the cranial nerves had the worst prognosis.

Suicide by air rifle and shotgun.

We report the case of a 39-year old white male who committed suicide by shooting himself with an air rifle and a shotgun. The ballistics of air guns and rifles, with particular reference to the Sheridan air rifle, are reviewed. Only two cases of multiple firearm suicide have been reported; both involved simultaneously fired handguns. Ours is the first case, to our knowledge, of an air rifle and a shotgun used in sequence to commit suicide.

Myopathy and fatal cardiopathy due to cytochrome c oxidase deficiency.

A 3-day-old girl had a syndrome of lethargy and lactic acidosis. Pregnancy and delivery had been normal; there was no consanguinity or family history of neuromuscular disease. At age 4 1/2 months, she had generalized weakness, hypotonia, areflexia, and macroglossia. She developed cyanosis and respiratory failure, and marked cardiomegaly was noted. She died at age 8 1/2 months of cardiac arrest. Results from a muscle biopsy specimen obtained at age 4 1/2 months showed ragged-red fibers and increased glycogen and lipid droplets. With the cytochrome c oxidase reaction, only 5% of the fibers stained positively in the biopsy specimen. Cytochrome c oxidase activity was 7.3% of normal in muscle mitochondria and 12.2% of normal in heart mitochondria. Reduced-minus-oxidized cytochrome spectra showed lack of the cytochrome aa3 peak. Immunotitration using antibodies against purified human heart cytochrome c oxidase showed normal amount of cross-reacting material in both heart and muscle. The genetic error could have involved a cytochrome c oxidase isozyme common to heart and muscle.

Sibs with the fetal akinesia sequence, fetal edema, and malformations: a new syndrome?

Pena and Shokeir [J Pediatr 85:373-375. 1974] first described a syndrome characterized by multiple ankyloses, camptodactyly, facial anomalies, and pulmonary hypoplasia, which was later termed Pena-Shokeir I syndrome. Recent evidence suggests that a more accurate designation for this condition is the fetal akinesia sequence, which is almost certainly a heterogeneous entity. We describe sibs who were diagnosed as having Pena-Shokeir I syndrome but who did not have the muscular or anterior horn cell changes characteristic of other infants with the fetal akinesia sequence. In addition, both sibs had fetal edema, the first sib had coarctation of the aorta, and the second had polydactyly and thyroid hypoplasia. We suggest that this case provides further evidence for heterogeneity in the fetal akinesia sequence and may represent a provisionally unique syndrome.

Bilateral pulmonary agenesis: association with the hydrolethalus syndrome and review of the literature from a developmental field perspective.

Only a few cases of bilateral pulmonary agenesis have been reported. Recently we saw such a case in an infant with the hydrolethalus syndrome. This observation seems to indicate that bilateral pulmonary agenesis is a severe expression of a developmental field defect that usually is represented by abnormal lung lobation or hypoplasia. The previously reported cases are discussed from the perspective of the developmental field concept.

Pituitary oncocytoma. Indispensable role of electron microscopy in its identification.

Two surgically resected pituitary adenomas that appeared to be chromophobe or poorly granulated acidophil adenomas by light microscopy were correctly identified as oncocytomas by electron microscopy. The tumor cells ahd markedly hyperplastic, moderately pleomorphic mitochondria in the cytoplasm of virtually all cells. Scattered secretory granules were displaced to the periphery of the cytoplasm but the secretion type of pituitary cell remained obscure. Histochemical and immunocytochemical methods imperfectly characterized these unusual tumors. Even though these neoplasms have been considered rare, they are now being recognized more often after ultrastructural study. Eventually their pathobiologic features may be better understood. One of our patients was 24 years old and is the youngest patient, to our knowledge, in whom a pituitary oncocytoma has been documented.