Cutaneous Pigmented Neurofibroma in a Pig - Morphology and Immunohistochemical Profile.

Peripheral nerve sheath tumours are rare in pigs. In the present case, a juvenile female hybrid pig showed a solitary, pigmented, cutaneous mass. Histologically, it consisted of clustered melanin-laden, epithelioid cells as well as spindle cells forming bundles and nodules. The latter were surrounded by perineurial-like cells. Single Wagner-Meissner-like corpuscles were present. Immunohistochemically, the epithelioid cells expressed S100 protein, melan A and the p75 neurotrophin receptor (p75NTR). The spindle cells expressed S100, sex determining region Y-box 2, p75NTR, Krox20, growth associated protein 43 and glial fibrillary acidic protein. Perineurial-like cells were positive for p75NTR, α-smooth muscle actin and cytokeratin. Taken together, the histological und immunohistochemical findings support the diagnosis of a cutaneous pigmented neurofibroma.

[Primary meningioma of the optical nerve sheet in infancy as initial presentation of neurofibromatosis type 2]. / Primäres Meningeom des Nervus opticus im Säuglingsalter als Erstmanifestation einer Neurofibromatose Typ 2.

Intraorbital meningiomas are rare tumors, making up less than 4% of all intraorbital tumors. Intraorbital meningiomas of childhood are curiosities with only few documented cases. We present the case of an 8­month-old male infant, presenting with strabismus and nystagmus. Magnetic resonance imaging showed a long segment thickening of the optical nerve and an intraocular tumor. The tumor was suspicious for retinal dysplasia and enucleation of the eye was performed to exclude malignancy. Histological examination revealed a meningothelial meningioma (WHO grade I), extending along the optical nerve and into the eye accompanied by retinal dysplasia and epiretinal membranes. Meningiomas of childhood, retinal dysplasia, and epiretinal membranes are regularly associated with neurofibromatosis type 2. Subsequent genetic analysis led to the final diagnosis. This case documents a very unusual early beginning of a neurofibromatosis type 2.

Subarachnoid hemorrhage due to aneurysm rupture in a young woman with Alagille syndrome - A rare cause of sudden death.

The Alagille syndrome (AGS) or arteriohepatic dysplasia is a rare, autosomal dominant inherited disease with a prevalence of approximately 1:100,000. AGS was first described in 1969 and affects liver, heart, arterial blood vessels, skeleton and the eyes. The expression of AGS is variable. In severe cases a liver transplantation is required. Presented is the case of a 25-year-old woman with AGS. At the age of 7 and 8years she had liver transplantations. Other typical findings associated with Alagille syndrome (e.g. pulmonary or renal anomalies) were also present. The young woman apparently died suddenly and unexpectedly in a good health condition despite regular medical treatment. Cause of death was a subarachnoid hemorrhage with invasion of the hemorrhage into the ventricle system caused by a rupture of previously unknown large aneurysm in the terminal basilary artery. Intracranial vascular malformations are a common finding in patients with AGS and cause death in up to 16% of them. Life expectancy in AGS patients depends on the severity of changes of the affected liver. But AGS is also responsible for various vascular abnormalities in several other organs which can cause lethal complications. Due to the high rate of vascular complications and intracranial hemorrhage with the leading cause of mortality in patients with AGS, vascular screening by the use of noninvasive imaging techniques (CT or MR angiography) is required to avoid unexpected sudden death.

[Orbital metastasis of a previously unknown lung carcinoma mimicking posterior ischemic optic neuropathy]. / Orbitale Metastase eines bis dato unbekannten Lungenkarzinoms mit klinischem Aspekt einer posterioren ischämischen Optikusneuropathie.

A 65-year-old patient presented with increasing loss of vision in the right eye. A relative afferent pupillary defect as well as visual field perimetry deficits in an otherwise unremarkable eye led to the presumed diagnosis of ischemia of the optic nerve; however, further imaging revealed an extensive necrotic bronchial carcinoma in the left upper lobe metastasizing to the orbit with compression of the optic nerve. The clinical and histological features are discussed with respect to possible primary origins of orbital metastases.

Unilateral cerebellar hypoplasia and mesencephalic malformation in a Hanoverian foal.

Neurological cases, especially in foals, are rare in the daily practical work. The most common causes are traumata and infectious diseases of the central nervous system (CNS). This case report provides further insights into the wide spectrum of possible neuropathological lesions by detailing a complex malformation with unilateral neurological signs that occurred later post natum. Thus, clinicians should also be aware of malformations in case of respective neurological patients. A Hanoverian foal was presented with progressive ataxia. General and blood examination revealed no further alterations. By neurologic examination, a unilateral hypermetria was diagnosed and a cysternography of the head was performed. A cerebellar malformation was assumed and the foal was euthanized due to poor prognosis. At necropsy, a unilateral absence of a cerebellar hemisphere and vermis accompanied by contralateral malformation of the mesencephalon was diagnosed. The missing areas of the right cerebellar hemisphere were replaced by a cystic formation. The left part of the mesencephalic lamina quadrigemina was reduced in size and the corpus callosum was hypoplastic. Additional microscopical findings were most obvious near the cyst formation and included angiofibrosis in remaining cerebellar and mesencephalic parenchyma and leptomeninges, heterotopia of cerebellar neurons, sclerosis in cerebellar cortex, focal proliferation of meningeal cells and mild mononuclear perivascular infiltrates. Occassional irregular neuronal arrangement in the mesencephalon was also present. Infectious agents such as Borna disease virus, rabies virus, and equine herpesvirus were not detected. Therefore, the complex malformation in this foal might have been caused by a destructive, possibly ischemic event, or could represent a sequel of a primary retrocerebellar cyst with accompanying compression of adjacent parenchyma.

Aprosencephaly with otocephaly in a lamb (Ovis aries).

Aprosencephaly is a rare condition in veterinary and human medicine characterized by the complete absence of telencephalon and diencephalon. Some cases are accompanied by a facial dysmorphism designated as otocephaly. A stillborn lamb had splanchnocranial anomalies that were classified by computed tomography, magnetic resonance imaging, and pathologic examination as aprosencephaly and otocephaly. The brain included parts of the cerebellum and brainstem but no telencephalon, diencephalon, or mesencephalon. The cerebellum had a structurally normal cortex with expression of neuronal nuclear antigen in the inner and doublecortin in the outer granular cell layers, as well as an irregularly situated nucleus dentatus. Aprosencephaly with otocephaly has been described in mice with heterozygous mutations in the Otx2 gene; however, no causative polymorphisms were detected in the Otx2 gene region of this lamb.

[Brainstem encephalitis in an 8-year-old girl]. / Hirnstammenzephalitis eines 8-jährigen Mädchens: Seltene Todesursache.

Encephalitis is often caused by viral infections and can affect various brain regions. The clinical symptoms are highly variable. Oligosymptomatic cerebral infections may remain undetected but there are also cases with very severe symptoms (e.g. paralysis, convulsions). This article presents the case of an 8-year-old girl who suffered from headaches and vomiting for several days following a harmless fall with impact on the back of the head. The health condition decreased rapidly and 7 days after the fall the girl was presented to a children's hospital. After a further foudroyant course of the disease the girl was hospitalized 2 days later. Resuscitation became necessary due to convulsions and pulmonary obstruction. Cranial computed tomography (cCT) revealed temporal hypodense areas and local edema. Cardiac echocardiography revealed a decreased left ventricular pump function so that encephalitis and myocarditis were suspected. Despite antiviral and antibiotic therapy the girl died 4 days after admission due to intravital brain death and multiorgan failure. This cause of death was confirmed by forensic autopsy. The fall had not led to any intracranial injury and predisposing diseases were not found. Histological examination revealed necrotizing brainstem encephalitis.

PTPIP51, a positive modulator of the MAPK/Erk pathway, is upregulated in glioblastoma and interacts with 14-3-3ß and PTP1B in situ.

Glioblastoma multiforme (GBM) is the most common and most malignant primary brain tumour. Protein tyrosine phosphatase interacting protein 51 (PTPIP51) is an interaction partner of 14-3-3ß, which correlates with the grade of malignancy in gliomas. In this study PTPIP51 and its interacting partners 14-3-3ß, PTP1B, c-Src, Raf-1 as well as EGFR were investigated in human glioblastoma. Twenty glioblastoma samples were analyzed on transcriptional and translational level by immunohistochemistry, in situ hybridization and RT-PCR. To compare PTPIP51 expression in gliomas of different malignancies, quantitative RT-PCR for grade II astrocytoma and GBM samples was employed. Additionally, we analyzed the correlation between PTPIP51 and 14-3-3ß transcription, and checked for in situ interaction between PTPIP51 and 14-3-3ß and PTP1B, respectively. PTPIP51 and 14-3-3ß mRNA showed a tumour grade dependent upregulation in gliomas. Glioblastoma cells displayed a strong immunoreaction of PTPIP51, which co-localized with 14-3-3ß and PTP1B. The duolink proximity ligation assay corroborated a direct in situ interaction of PTPIP51 with both proteins, known to interact with PTPIP51 in vitro. The in vitro interacting partners Raf-1 and c-Src showed a partial co-localization. Besides, immune cells located in capillaries or infiltrating the tumour tissue and endothelial cells of pseudoglomerular vessels revealed a high PTPIP51 expression. The upregulation of PTPIP51 and its connection with the EGFR/MAPK pathway by 14-3-3ß via Raf-1 and by PTP1B via c-Src, argue for a functional role of PTPIP51 in the pathogenesis of human glioblastoma.

Histological examination of the pituitary glands in cases of fatal hypothermia.

Besides typical macroscopical findings in cases of death due to hypothermia (frost erythema, haemorrhagic gastric erosions) there are some histological changes (e.g. lipid accumulation in epithelial cells of renal proximal tubules) which can help to determine the cause of death. In the literature some changes of the pituitary gland are described in case of hypothermia, e.g. haemorrhage and hyperaemia of the anterior lobe of the pituitary gland (adenohypophysis) or a vacuolization of cells in the anterior pituitary. The validity of these morphological changes as hypothermia marker should be proved in our autopsy material. 17 pituitary glands in cases with verified fatal accidental hypothermia were examined histologically and immunohistochemically (HE, Ferric, Azan, LCA, C5b9) and compared with 61 pituitary glands of a matching control group (cases of natural and non-natural death without trauma and long agonal period). Autolytical changes complicated an evaluation but in 5.9% of the study group and 1.6% of the control group a vacuolization of cells could be verified. In none of the examined cases a distinct haemorrhage into the glandular tissue was detected. Histopathological characteristics which are described in the literature as pathogenetic for hypothermia could not be found. Differences concerning histological characteristics of the pituitary glands between cases of fatal hypothermia and the control group were not observed.

First manifestation of lambda positive plasmacytoma in the orbital apex with acute unilateral loss of vision.

INTRODUCTION: An intracranial plasmacytoma is a rare form, which can involve the calvarium, dura or the cranial base. Only few case reports describe the manifestation of plasmacytoma of the skull base with affection of visual acuity. CASE REPORT: We describe the case of a 43-year-old woman, presenting with an acute unilateral loss of vision. The presumption diagnosis was retrobulbar neuritis as first manifestation of multiple sclerosis. MR imaging disclosed a tumour in the left orbital region and a meningioma was suspected. After complete resection with decompression of the optic nerve, the neuropathological examination revealed a lambda positive plasmacytoma. Additional work-up disclosed an involvement of multiple vertebral bodies. Due to the diagnosis of multiple myeloma, oncological therapy had been initiated. CONCLUSION: Skull base plasmacytoma is a rare disease. Solitary lesions causing neurological deficits should be treated aggressively including surgery for histological diagnosis and decompression of neural structures. Prognosis and further therapy depends on the systemic stage of disease, which has to be defined by diagnostic work-up.

Progressive biological behavior of a dysembryoplastic neuroepithelial tumor.

We present the case of a 13-month-old girl with a right occipital cortical alteration on MRI that proved to be a growing lesion. Tumor growth had been observed over a period of 15 months before total resection was performed, revealing a dysembryoplastic neuroepithelial tumor WHO grade I. This case shows that dysembryoplastic neuroepithelial tumors can present as growing neoplasias. It underlines the importance of obtaining histologic diagnosis and close follow-up examinations using MRI, even in so-called stable lesions that are only unveiling through epileptic seizures.

T-cell lymphoma mimicking schwannoma of a cervical nerve root.

T-cell lymphoblastic lymphoma is a rare form of non-Hodgkin lymphoma, which shows preponderance for young men. Most common symptoms are painless swelling of lymph nodes, accompanied by B symptoms and large mediastinal masses. Most often, an involvement of the nervous system is due to paraneoplastic symptoms or side effects of treatment. In a literature research, we could not find a case with affection of a cervical nerve root as the first symptom for T-cell lymphoblastic lymphoma. A 39-year-old man presented with right-sided C8 radiculopathy, including pareses and paresthesia. Since the magnetic resonance image disclosed a right-sided mass lesion in the region of the neuroforamen C8, compressing the corresponding nerve root, a schwannoma was suspected. The tumor was removed using a dorsal approach. Neuropathological examination revealed the diagnosis of T-cell lymphoblastic lymphoma. The patient underwent diagnostic staging and received further treatment. He experienced a very grim course and succumbed to his disease 12 months after surgery. T-cell lymphoblastic lymphoma is a rare disease, and tropism of lymphoma cells to neural structures is seldom encountered. However, the presence of radiculopathy, together with signs, referring to B symptoms, should prompt the physician to consider this coincidence in the differential diagnosis of schwannoma.

Diffuse intracranial oligodendroglioma in a cow.

This report describes the clinical, morphological and immunohistochemical findings in an adult cow with cerebral oligodendroglioma. The tumour extended from the metencephalon to the telencephalon, with infiltration of the meninges. Immunohistochemically, the tumour cells lacked expression of a specific tumour antigen, were partially positive for S-100 and tau protein, and were negative for a range of antigens including glial fibrillary acid protein, neuron-specific enolase, myelin basic protein and synaptophysin. This is the first report describing a diffuse, cerebral oligodendroglioma in a cow.

[Acanthamoeba meningoencephalitis: a case in an adolescent female patient with systemic lupus erythematosus]. / Acanthamöben-Meningoenzephalitis : Ein Fall bei einer jugendlichen Patientin mit systemischem Lupus erythematodes.

Meningoencephalitis caused by Acanthamoeba spp . is a rare opportunistic infection, difficult to diagnose and difficult to treat, which causes death in almost all cases. We report the neuropathologic findings of a 16-year-old girl with systemic lupus erythematosus (SLE) treated with immunosuppression who died of fulminant Acanthamoeba meningoencephalitis. Neuropathologic examination revealed multiple supratentorial and infratentorial hemorrhagic necrotizing lesions with encephalitis and vasculitis with mixed inflammatory infiltrates, fibrinoid necrosis of vessel walls, and local leptomeningitis. Acanthamoeba in the lesions may be misinterpreted as macrophages. Taking them into differential diagnostic consideration, cytological differences should be detected, and relevant additional stains for reliable differentiation of these cells can be performed. To our knowledge, this is the first published case of Acanthamoeba meningoencephalitis in a patient with SLE in Germany.

Metastatic tumours mimicking vestibular schwannoma.

In this review of the literature we discuss the rare occurrence of metastatic tumours mimicking bilateral vestibular schwannoma and present an own case with pancreatic signet-ring cell carcinoma as primary tumour.

Extraventricular neurocytoma of the spinal cord in a dog.

Central neurocytoma is a rare, prognostically favorable neuronal tumor of the human central nervous system, typically located intraventricularly near the foramen of Monro. Extraventricular cerebral neurocytomas and spinal tumors have also been reported. To date, however, neurocytomas have not been documented in domestic animal species. In this report, we describe a spinal cord tumor in a dog. The microscopic examination revealed tumor cells forming loosely packed clusters in some areas and palisades in other areas. In addition, they showed fine fibrillary neuropil-like areas of different sizes, sometimes resembling the "rosettes" of pineocytomas, as well as ependymoma-like perivascular pseudorosettes. The tumor cells had scant eosinophilic cytoplasm, with perinuclear halos, closely resembling the appearance of oligodendroglioma. Immunohistochemical staining showed expression of synaptophysin and neuron-specific enolase by tumor cells and pronounced in fibrillary areas. On the basis of histomorphology and immunohistochemical reactivity, the present tumor was diagnosed as extraventricular neurocytoma.