White Matter Diseases with Radiologic-Pathologic Correlation.

White matter diseases include a wide spectrum of disorders that have in common impairment of normal myelination, either by secondary destruction of previously myelinated structures (demyelinating processes) or by primary abnormalities of myelin formation (dysmyelinating processes). The pathogenesis of many white matter diseases remains poorly understood. Demyelinating disorders are the object of this review and will be further divided into autoimmune, infectious, vascular, and toxic-metabolic processes. Autoimmune processes include multiple sclerosis and related diseases: tumefactive demyelinating lesions, Balo concentric sclerosis, Marburg and Schilder variants, neuromyelitis optica (Devic disease), acute disseminated encephalomyelitis, and acute hemorrhagic leukoencephalopathy (Hurst disease). Infectious processes include Lyme disease (neuroborreliosis), progressive multifocal leukoencephalopathy, and human immunodeficiency virus (HIV) encephalopathy. Vascular processes include different types of small-vessel disease: arteriolosclerosis, cerebral amyloid angiopathy, cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), primary angiitis of the central nervous system, Susac syndrome, and neurolupus. Toxic-metabolic processes include osmotic myelinolysis, methotrexate leukoencephalopathy, and posterior reversible encephalopathy syndrome. The imaging spectrum can vary widely from small multifocal white matter lesions to confluent or extensive white matter involvement. Understanding the pathologic substrate is fundamental for understanding the radiologic manifestations, and a systematic approach to the radiologic findings, in correlation with clinical and laboratory data, is crucial for narrowing the differential diagnosis. (©)RSNA, 2016.

Characterisation of interface astroglial scarring in the human brain after blast exposure: a post-mortem case series.

BACKGROUND: No evidence-based guidelines are available for the definitive diagnosis or directed treatment of most blast-associated traumatic brain injuries, partly because the underlying pathology is unknown. Moreover, few neuropathological studies have addressed whether blast exposure produces unique lesions in the human brain, and if those lesions are comparable with impact-induced traumatic brain injury. We aimed to test the hypothesis that blast exposure produces unique patterns of damage, differing from that associated with impact-induced, non-blast traumatic brain injuries. METHODS: In this post-mortem case series, we investigated several features of traumatic brain injuries, using clinical histopathology techniques and markers, in brain specimens from male military service members with chronic blast exposures and from those who had died shortly after severe blast exposures. We then compared these results with those from brain specimens from male civilian (ie, non-military) cases with no history of blast exposure, including cases with and without chronic impact traumatic brain injuries and cases with chronic exposure to opiates, and analysed the limited associated clinical histories of all cases. Brain specimens had been archived in tissue banks in the USA. FINDINGS: We analysed brain specimens from five cases with chronic blast exposure, three cases with acute blast exposure, five cases with chronic impact traumatic brain injury, five cases with exposure to opiates, and three control cases with no known neurological disorders. All five cases with chronic blast exposure showed prominent astroglial scarring that involved the subpial glial plate, penetrating cortical blood vessels, grey-white matter junctions, and structures lining the ventricles; all cases of acute blast exposure showed early astroglial scarring in the same brain regions. All cases of chronic blast exposure had an antemortem diagnosis of post traumatic stress disorder. The civilian cases, with or without history of impact traumatic brain injury or a history of opiate use, did not have any astroglial scarring in the brain regions analysed. INTERPRETATION: The blast exposure cases showed a distinct and previously undescribed pattern of interface astroglial scarring at boundaries between brain parenchyma and fluids, and at junctions between grey and white matter. This distinctive pattern of scarring may indicate specific areas of damage from blast exposure consistent with the general principles of blast biophysics, and further, could account for aspects of the neuropsychiatric clinical sequelae reported. The generalisability of these findings needs to be explored in future studies, as the number of cases, clinical data, and tissue availability were limited. FUNDING: Defense Health Program of the United States Department of Defense.

Clinical and laboratory features distinguishing juvenile polymyositis and muscular dystrophy.

OBJECTIVE: To differentiate juvenile polymyositis (PM) and muscular dystrophy, both of which may present with chronic muscle weakness and inflammation. METHODS: We studied 39 patients with probable or definite juvenile PM and 9 patients with muscular dystrophies who were initially misdiagnosed as having juvenile PM. Differences in demographic, clinical, and laboratory results; outcomes; and treatment responses were evaluated by Fisher's exact and rank sum tests. Random forests classification analysis and logistic regression were performed to examine significant differences in multivariable models. RESULTS: Clinical features and serum muscle enzyme levels were similar between juvenile PM and dystrophy patients, except 89% of dystrophy patients had muscle atrophy compared with 46% of juvenile PM patients. Dystrophy patients had a longer delay to diagnosis (median 12 versus 4 months) and were less frequently hospitalized than juvenile PM patients (22% versus 74%). No dystrophy patients, but 54% of juvenile PM patients, had a myositis autoantibody. Dystrophy patients more frequently had myopathic features on muscle biopsy, including diffuse variation of myofiber size, fiber hypertrophy, and myofiber fibrosis (44-100% versus 8-53%). Juvenile PM patients more frequently had complex repetitive discharges on electromyography and a complete response to treatment with prednisone or other immunosuppressive agents than dystrophy patients (44% versus 0%). Random forests analysis revealed that the most important features in distinguishing juvenile PM from dystrophies were myositis autoantibodies, clinical muscle atrophy, and myofiber size variation on biopsy. Logistic regression confirmed muscle atrophy, myofiber fibrosis, and hospitalization as significant predictors. CONCLUSION: Muscular dystrophy can present similarly to juvenile PM. Selected clinical and laboratory features are helpful in combination in distinguishing these conditions.

Neuroimaging of a pilocytic astrocytoma with anaplastic features and diffusion tensor imaging characteristics.

We report the MRI findings of an adult patient with a (rare in adults) biopsy-proven pilocytic astrocytoma with anaplastic features. Diffusion tensor imaging may potentially provide information on cell proliferation, vascularity, and fiber destruction, which can have implications for treatment and prognosis. In this case, tractography and fractional anisotropy maps demonstrated displacement of adjacent parenchyma and relatively intact fractional anisotropy, suggesting a pilocytic rather than an anaplastic astrocytoma.

Dysembryoplastic neuroepithelial tumor with atypical presentation: MRI and diffusion tensor characteristics.

We report the neuroimaging findings of a 26-year-old female patient with a biopsy-proven dysembryoplastic neuroepithelial tumor (DNET). DNETs are an uncommon, usually benign, glial-neural cortical neoplasm of children and young adults who typically present with intractable seizures. DNETs may occur in any region of the supratentorial cortex, but have a predilection for the temporal lobes. Accurate neuroimaging diagnosis is essential since patients with DNET benefit from complete resection. However, accurate differentiation from other cortical lesions may be challenging. Typical conventional Magnetic Resonance Imaging (MRI) features can help in the differentiation from other similar cortical tumors. Diffusion tensor imaging can also provide important additional diagnostic information regarding the degree of involvement of adjacent parenchyma and white matter tracts. In this case, tractography and fractional anisotropy maps demonstrated that fiber tracts surrounding the lesion were displaced, but fiber integrity was maintained, which is more suggestive of a DNET rather than a more aggressive neoplasm. Accurate identification of DNETs is essential for the purpose of rendering a timely diagnosis and start appropriate treatment.

Relapsed acute myelogenous leukemia of brachial plexus after marrow transplant.

We present a detailed description of brachial plexus infiltration by acute myelogenous leukemia (AML) in the setting of a remission bone marrow biopsy, without evidence of leukemia by flow cytometric analysis. This case illustrates the possibility of dormant leukemic cells in the peripheral nervous system (PNS) in a patient in apparent clinical remission. In patients with an unexplained brachial plexopathy and a history of AML, leukemic infiltrate of the PNS must be considered.

Fourth ventricular chordoid meningioma.

The chordoid variant of meningioma is a histological subtype which carries with it a more aggressive clinical course and a propensity for recurrence. Similar to other meningioma subtypes, this lesion is encountered typically in the supratentorial compartment, often along the cerebral convexities. The chordoid meningioma subtype is found primarily in the adult population, and may occasionally be associated with the systemic manifestations of Castleman's disease. We present an adult patient with a rare chordoid meningioma located within the fourth ventricle. This lesion was treated with gross total resection. Chordoid meningioma must be considered within the differential diagnosis of intraventricular tumors. This histological subtype of meningioma warrants close follow-up. The patient must also be evaluated for systemic manifestations of Castleman's disease.

Cerebellar medulloblastoma in the elderly.

Although medulloblastoma is the most common central nervous system malignancy in children, cases are much less common in adults. Moreover, this tumor is exceedingly rare in patients older than 65 years. Analysis of previous case reports reveals that medulloblastoma in the elderly is more commonly seen in males in a lateral location; histologically, medulloblastomas in aged individuals usually belong to the classic subtype. During intraoperative consultation, the pathologist should consider medulloblastoma in the differential diagnosis of a cerebellar mass in the elderly because cytologic features may overlap with metastatic small cell carcinoma or lymphoma. We present a case of medulloblastoma in a 66-year-old man and review the literature on the subject.

Cranial nerve hemangioblastomas. Report of a rare case and review of literature.

BACKGROUND: Cranial nerve hemangioblastomas are exceedingly rare lesions. We review available literature and present the first surgical report on a solid hemangioblastoma arising from the trigeminal nerve and involving the Meckel cave that was successfully treated with selective embolization and successive surgical resection. CASE DESCRIPTION: A 54-year-old woman presented with an 8-month history of facial numbness associated with headache. An MRI revealed a highly vascularized supra- and infratentorial mass involving the right Meckel cave. A preoperative angiogram with selective embolization of tumoral feeders was performed, and the patient elected to undergo surgical treatment. A large solid lesion encasing the trigeminal nerve was resected without complications via a PLPA approach. Hystopathological examination revealed features consistent with the diagnosis of hemangioblastoma. Other stigmata or familiar history of VHL disease were absent. CONCLUSIONS: Review of the literature confirms that cranial nerve hemangioblastomas are very rare lesions that occur sporadically or in association with VHL disease. Surgical management of such lesions should be directed by clinical and radiological features as well as patient expectations.

Intradural cranial chordoma: a rare presentation of an uncommon tumor. Surgical experience and review of the literature.

OBJECT: Intracranial intradural chordomas are extremely rare lesions, and only a few cases have been reported in the neurosurgical literature. The authors performed a retrospective analysis of cases treated at their institutions. They present an illustrative surgical scenario and discuss the published literature, pathogenesis, and histopathological features as well as available follow-up data on the clinical behavior of these intradural lesions. METHODS: The authors reviewed clinical, neuroimaging, operative and follow-up data from a series of 79 chordomas treated at their institutions over the last 17 years. They found that the tumors were confined exclusively to the intradural compartment in only three cases. Staining for MIB-1 was performed to support the differential diagnosis between ecchordosis physaliphora and intradural chordoma, and in all three patients the neoplastic nature of the lesions was confirmed. None of these three cases showed recurrence of the lesion at midterm follow up. CONCLUSIONS: Complete resection, followed by close clinical and neuroradiological follow up, is warranted in cases of intradural cranial chordoma.

Multiple metachronous brain metastases from primary ureteral carcinoma.

Transitional cell carcinoma (TCC) of the ureter is an uncommon urologic malignancy, with approximately 150 cases diagnosed annually. Metastatic brain disease from ureteral TCC is exceedingly rare. To our knowledge, our case report represents only the second report of brain metastasis from ureteral TCC and the only reported patient to undergo resection of their TCC brain metastasis.

Granulosa cell tumor and mucinous cystadenoma arising in a mature cystic teratoma of the ovary: A unique case report and review of literature.

Mature cystic teratoma of the ovary, though it contains derivatives of all three embryonic germ cell layers, rarely presents together with ovarian epithelial or sex cord-stromal tumors. Only a few cases of ovarian cystic teratoma in association with granulosa cell tumor have been reported in the literature, and simultaneous occurrence of mucinous cystadenoma and granulosa cell tumor is even rarer. To our knowledge, there has never been a report of mature cystic teratoma of ovary coexisting with granulosa cell tumor and mucinous cystadenoma. We report a case of mature cystic teratoma, mucinous cystadenoma, and granulosa cell tumor in the ovary of a 40-year-old woman. The involved ovary, massively enlarged by a multiloculated cyst, showed a hair-sprouting mass with a yellow-tan nodule embedded in the cyst wall. Microscopically, three tumor types were revealed: mature cystic teratoma, mucinous cystadenoma, and granulosa cell tumor.

Pericytic-like angiotropism of glioma and melanoma cells.

We have identified in malignant melanoma an angiotumoral complex in which tumor cells occupy a pericytic location along the endothelium of microvessels without evidence of intravasation. We have suggested that this pericytic-like angiotropism could be a marker of an extravascular migration of tumor cells along the abluminal surface of vessels. The extravascular migratory metastasis proposed for melanoma has close analogies with glioma migration. To compare our hypothesis of extravascular migration by melanoma with the migration of glioma cells, we have used the B16 murine melanoma cell line and the GL26 murine glioma cell line in an in vivo murine brain tumor model and in vitro using endothelial cells that have formed capillary-like structures and have been cocultivated with tumor cells. In the brain tumors, a clear progression of glioma and melanoma cells was observed along the abluminal surface of vessels, where they occupied a pericytic location along the periendothelial laminin. In vitro, time-lapse videomicroscopy recorded the migration of tumor cells toward endothelial tubules. After 24 hours, both the melanoma cells and the glioma cells were localized along the external surfaces of the vascular tubules, occupying a pericytic-like location. These similarities between glioma and melanoma support the hypothesis of an extravascular migration of melanoma cells, particularly along the abluminal surface of vessels.

Cutaneous metastasis from an intracranial glioblastoma multiforme.

A 34-year-old white man with a history of an intracranial glioblastoma multiforme was treated with surgical excision and radiotherapy. Five months later, the patient had a rapidly growing scalp mass develop. This lesion was excised, and the histology revealed a tumor that was similar to the originally resected intracranial glioblastoma. Immunohistochemistry for general neuroepithelial derivation (S-100 protein) and for glial fibrillary acidic protein (GFAP) was positive, whereas mesenchymal, epithelial, and neuronal markers were negative. This immunohistochemistry pattern was identical to the original tumor. Although metastasis of this tumor is not uncommon, metastasis to the skin has never been reported. To our knowledge, this is the first reported case of cutaneous metastasis from glioblastoma in the world literature.