Bilateral Inferior Rectus Schwannoma and Strabismus: A Case Report.

Schwannomas, also known as neurilemomas, are peripheral nerve sheath neoplasms. They can be sporadic or associated with genetic syndromes including neurofibromatosis type 2 (NF2). Schwannomas may lead to symptoms by exerting pressure on nearby structures, such as nerve and muscle fibers. In this study, we present the case of a 22-year-old female with a history of NF2 who, upon examination, presented with a visibly enlarged salmon-colored mass involving the left inferior rectus that she had since the age of 12 years. Ocular examinations revealed a small left hypertropia and exotropia in all gazes. Magnetic resonance imaging confirmed bilateral involvement of the inferior rectus muscles. She had a partial excisional biopsy of the mass involving the left inferior rectus muscle that confirmed the presence of schwannoma. This case highlights the importance of comprehensive evaluation of sensory and motor functions as well as considering orbital schwannomas in cases of strabismus, especially within the context of neurofibromatosis.

Primary non-gestational mediastinal choriocarcinoma metastatic to the brainstem.

Choriocarcinoma is a highly malignant tumour emerging from the syncytiotrophoblast divided into gestational and non-gestational presentations. Primary choriocarcinoma of the mediastinum is rare. Metastases to the brain often occur; however, brainstem involvement has not been reported for non-gestational choriocarcinoma. We described a middle-aged man who developed a complete left oculomotor nerve paralysis secondary to a brainstem tumour at the midbrain. The workup for the primary source of the brainstem tumour included a chest CT scan, which revealed a mediastinal mass. A mediastinal mass needle biopsy confirmed the diagnosis of primary mediastinal choriocarcinoma. Despite aggressive chemotherapy, the patient died 6 months after the initial presentation from neurological complications and multiorgan failure.

Malignant peripheral nerve sheath tumour transformation of histological benign vestibular schwannoma after stereotactic radiosurgery in patients without neurofibromatosis.

Stereotactic radiosurgery (SRS) poses a minimal but important risk for tumour transformation, typically occurring 8-10 years after the treatment. Malignant peripheral nerve sheath tumour (MPNST) is the most common tumour arising from a vestibular schwannoma treated with SRS, with only 14 cases previously reported. We present the fifteenth case and describe its evolution and clinical course. A 56-year-old man without a history of neurofibromatosis was diagnosed 9 years prior with a vestibular schwannoma. SRS to the residual tumour was given 3 months later. During the current hospitalisation, he was reoperated where histology confirmed a MPNST. All 15 MPNST cases were analysed, showing a 77% female predominance presenting a malignant transformation at a mean age of 51. The diagnosis was made at a mean time of 74 months after SRS. The mean survival time after diagnosis was 16 months. MPNST arising from benign vestibular schwannoma after SRS treatment is an uncommon but devastating complication.

Primary diffuse large B cell lymphoma of the optic chiasm in an immunocompetent patient.

Primary lymphoma of the visual pathway is rare, especially at the chiasm. Very few cases have been reported. The lesion is frequently confused with an optic-hypothalamic glioma. A 55-year-old man was found disoriented at his home by a friend and evaluated with a brain MRI which demonstrated an expansile mass located at the optic chiasm and hypothalamus level. The principal differential was a high-grade hypothalamic glioma due to the contrast enhancement. A biopsy of the chiasmal lesion was performed. Histological diagnosis of the lesion was compatible with a diffuse large B cell lymphoma. He was started on methotrexate and rituximab; however, his clinical course kept deteriorating, and he died 64 days after his presentation. All prior cases of primary lymphoma of the chiasm are reviewed.

Isolated intestinal polyarteritis nodosa in an elderly patient.

Polyarteritis nodosa (PAN) is a necrotising systemic vasculitis involving medium-sized and small-sized vessels. PAN limited to a single organ is rare, particularly in the elderly population. Herein, we present a 73-year-old-woman who developed severe abdominal pain. Mesenteric angiography showed multifocal areas of segmental dilation and narrowing of the superior mesenteric, ileocolic and right colonic arteries. Exploratory laparotomy revealed multiple areas of necrosis of the jejunum for which resection was performed. Histopathological exam disclosed mesenteric vasculitis with fibrinoid necrosis of the arterial wall with leucocytic infiltrates and haemorrhages consistent with PAN. She was started on high-dose corticosteroids with an initial good response. However, 6 months later, she developed intestinal pseudo-obstruction for which oral cyclophosphamide was started. After 5 months of cyclophosphamide therapy, she remained stable without further relapses. Our case suggests that PAN should be considered in elderly patients presenting with abdominal pain even in the absence of systemic involvement.

Extraskeletal presentation of Ewing's Sarcoma.

The case of a 27-year-old Hispanic female who presented with an occipito-parietal tumor after suffering trauma to the area. A physical examination revealed no tenderness to palpation and with evidence of healing ulcerations. The biopsy was consistent with a synovial sarcoma. A wide excision of the mass (15cm x 14cm x 6cm) followed by a pericranial flap was performed. A follow-up CT showed recurrence involving the parietal sagittal sinus. After a second biopsy the mass was determined to be a small-cell sarcoma, consistent with Ewing's sarcoma. Chemotherapy included 8 cycles of doxorubicin, vincristine, and cyclophosphamide, with alternating cycles of etoposide and ifosfamide. A year later, a second wide excision of the mass was performed, followed by bilaminate skin substitute and skin graft placement for reconstruction of the soft-tissue defect. After chemotherapy, a follow-up PET scan showed no signs of re-uptake in any soft tissue or skeletal structures. After 2 years, the patient remains in complete remission.

Static and Dynamic Measurement of Dopamine Adsorption in Carbon Fiber Microelectrodes Using Electrochemical Impedance Spectroscopy.

In this study, electrochemical impedance spectroscopy was used for the first time to study the adsorption of dopamine in carbon fiber microelectrodes. In order to show a proof-of-concept, static and dynamic measurements were taken at potentials ranging from -0.4 to 0.8 V versus Ag|AgCl to demonstrate the versatility of this technique to study dopamine without the need of its oxidation. We used electrochemical impedance spectroscopy and single frequency electrochemical impedance to measure different concentrations of dopamine as low as 1 nM. Moreover, the capacitance of the microelectrodes surface was found to decrease due to dopamine adsorption, which is dependent on its concentration. The effect of dissolved oxygen and electrochemical oxidation of the surface in the detection of dopamine was also studied. Nonoxidized and oxidized carbon fiber microelectrodes were prepared and characterized by optical microscopy, scanning electron microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. Optimum working parameters of the electrodes, such as frequency and voltage, were obtained for better measurement. Electrochemical impedance of dopamine was determined at different concentration, voltages, and frequencies. Finally, dynamic experiments were conducted using a flow cell and single frequency impedance in order to study continuous and real-time measurements of dopamine.

Mitochondrial DNA Integrity Is Maintained by APE1 in Carcinogen-Induced Colorectal Cancer.

Changes in mitochondrial DNA (mtDNA) integrity have been reported in many cancers; however, the contribution of mtDNA integrity to tumorigenesis is not well understood. We used a transgenic mouse model that is haploinsufficient for the apurinic/apyrimidinic endonuclease 1 (Apex1+/-) gene, which encodes the base excision repair (BER) enzyme APE1, to determine its role in protecting mtDNA from the effects of azoxymethane (AOM), a carcinogen used to induce colorectal cancer. Repair kinetics of AOM-induced mtDNA damage was evaluated using qPCR after a single AOM dose and a significant induction in mtDNA lesions in colonic crypts from both wild-type (WT) and Apex1+/-animals were observed. However, Apex1+/- mice had slower repair kinetics in addition to decreased mtDNA abundance. Tumors were also induced using multiple AOM doses, and both WT and Apex1+/-animals exhibited significant loss in mtDNA abundance. Surprisingly, no major differences in mtDNA lesions were observed in tumors from WT and Apex1+/- animals, whereas a significant increase in nuclear DNA lesions was detected in tumors from Apex1+/- mice. Finally, tumors from Apex1+/- mice displayed an increased proliferative index and histologic abnormalities. Taken together, these results demonstrate that APE1 is important for preventing changes in mtDNA integrity during AOM-induced colorectal cancer.Implications: AOM, a colorectal cancer carcinogen, generates damage to the mitochondrial genome, and the BER enzyme APE1 is required to maintain its integrity. Mol Cancer Res; 15(7); 831-41. ©2017 AACR.

Atypical Fibroxanthoma.

Atypical fibroxanthoma is a malignant skin tumor with histologic features similar to those of undifferentiated pleomorphic sarcoma, but lacking its more aggressive behavior. The tumor is composed of pleomorphic cells with hyperchromatic nuclei and abundant cytoplasm, commonly arranged in a spindle cell pattern. Recent genetic studies have identified similarities between atypical fibroxanthoma and undifferentiated pleomorphic sarcoma, such as the presence of 9p and 13q deletions in both tumors, favoring a common histogenesis. However, the lack of K-ras and H-ras mutations in atypical fibroxanthoma compared with undifferentiated pleomorphic sarcoma could explain the difference in aggressiveness and continued separation of these entities. Exclusion of other neoplasms by histology and immunohistochemistry followed by complete surgical removal remains the standard of care.

Pheochromocytoma in pregnancy: A case Report.

This is the case of a 38 year-old female patient with an intrauterine pregnancy, in which a previous incidentally identified adrenal mass proved to be a pheochromocytoma during the antenatal period. The patient was started on α-and ß-adrenergic blockade to maintain hemodynamic stability, and surgical removal of the lesion was performed during the second trimester without major complications. In view of the rarity of this disorder in pregnancy, it is imperative to have a high index of suspicion for a prompt and dedicated management, since this tumor, if unrecognized, is associated with high fetal and maternal mortality.

Expression of Basal-like Biomarkers in Triple Negative Invasive Breast Carcinoma in Puerto Rico.

OBJECTIVE: Routine Progesterone and Estrogen hormone receptor proteins and human epidermal growth factor receptor 2 (HER-2) analysis on invasive breast carcinomas provide therapeutic and prognostic values, revealing significant subgroups: luminal A, luminal B, HER-2 and the "triple negative" tumors. The aim of this study was to determine the expression of basal cytokeratins and Epidermal Growth Factor Receptor in "triple negative" invasive breast carcinomas in Puerto Rico women. METHODS: All invasive breast carcinoma cases received from 2008 to 2010 were included. Assessment of tumoral expression of Estrogen Receptor, Progesterone Receptor and HER-2 was performed. The cases were divided into groups based on their molecular categories and analyzed according to the age. "Triple negative" tumors were further analyzed according to their expression of Epidermal Growth Factor Receptor and cytokeratins 5/6 and 14. RESULTS: From 717 cases reviewed, 487 cases of invasive breast carcinoma were included. The molecular categories were 66%, 10%, 9% and 15% for the luminal A, luminal B, Her-2 and "triple negative" groups, respectively. No significant difference (p= 0.64) was observed between the molecular categories and the age of the patients. Assessment of basal cytokeratins and Epidermal Growth Factor Receptor expression was performed on 41 "triple negative" tumors; 71% expressed at least one basal cytokeratin or Epidermal Growth Factor Receptor and 29% were negative to all markers. CONCLUSION: Prevalence and relation between the molecular categories and the expression of basal cytokeratins in "triple negative" tumors in our population is comparable to other published data.

4R-cembranoid protects against diisopropylfluorophosphate-mediated neurodegeneration.

Many organophosphorous esters synthesized for applications in industry, agriculture, or warfare irreversibly inhibit acetylcholinesterase, and acute poisoning with these compounds causes life-threatening cholinergic overstimulation. Following classical emergency treatment with atropine, an oxime, and a benzodiazepine, surviving victims often suffer brain neurodegeneration. Currently, there is no pharmacological treatment to prevent this brain injury. Here we show that a cyclic diterpenoid, (1S,2E,4R,6R,7E,11E)-cembra-2,7,11-triene-4,6-diol (4R) ameliorates the damage caused by diisopropylfluorophosphate (DFP) in the hippocampal area CA1. DFP has been frequently used as a surrogate for the warfare nerve agent sarin. In rats, DFP is lethal at the dose used to cause brain damage. Therefore, to observe brain damage in survivors, the death rate was reduced by pre-administration of the peripherally acting antidotes pyridostigmine and methyl atropine or its analog ipratropium. Pyridostigmine bromide, methyl atropine nitrate, and ipratropium bromide were dissolved in saline and injected intramuscularly at 0.1mg/kg, 20mg/kg, and 23mg/kg, respectively. DFP (9mg/kg) dissolved in cold water was injected intraperitoneally. 4R (6mg/kg) dissolved in DMSO was injected subcutaneously, either 1h before or 5 or 24h after DFP. Neurodegeneration was assessed with Fluoro-Jade B and amino cupric silver staining; neuroinflammation was measured by the expression of nestin, a marker of activated astrocytes. Forty-eight hours after DFP administration, 4R decreased the number of dead neurons by half when injected before or after DFP. 4R also significantly decreased the number of activated astrocytes. These data suggest that 4R is a promising new drug that could change the therapeutic paradigm for acute poisoning with organophosphorous compounds by the implementation of a second-stage intervention after the classical countermeasure treatment.

Manganese superoxide dismutase: guardian of the powerhouse.

The mitochondrion is vital for many metabolic pathways in the cell, contributing all or important constituent enzymes for diverse functions such as ß-oxidation of fatty acids, the urea cycle, the citric acid cycle, and ATP synthesis. The mitochondrion is also a major site of reactive oxygen species (ROS) production in the cell. Aberrant production of mitochondrial ROS can have dramatic effects on cellular function, in part, due to oxidative modification of key metabolic proteins localized in the mitochondrion. The cell is equipped with myriad antioxidant enzyme systems to combat deleterious ROS production in mitochondria, with the mitochondrial antioxidant enzyme manganese superoxide dismutase (MnSOD) acting as the chief ROS scavenging enzyme in the cell. Factors that affect the expression and/or the activity of MnSOD, resulting in diminished antioxidant capacity of the cell, can have extraordinary consequences on the overall health of the cell by altering mitochondrial metabolic function, leading to the development and progression of numerous diseases. A better understanding of the mechanisms by which MnSOD protects cells from the harmful effects of overproduction of ROS, in particular, the effects of ROS on mitochondrial metabolic enzymes, may contribute to the development of novel treatments for various diseases in which ROS are an important component.

Divertículo de Meckel en el paciente adulto. Experiencia en la Fundación Santa Fe de Bogotá / Meckel`s diverticulum in the adult patient. Experience in the Foundation Santa Fe of Bogota

OBJETIVOS: Establecer las características clínicas, evolución y manejo de los pacientes con diagnóstico definitivo de divertículo de Meckel manejados entre 1991 y 2003 por la sección de Cirugía General del Hospital Universitario de la Fundación Santa Fe de Bogotá. MATERIALES Y MÉTODOS: Mediante un estudio observacional descriptivo tipo serie de casos se revisaron las historias clínicas de los 13 pacientes que tuvieron como diagnóstico histopatológico un divertículo de Meckel desde 1991 hasta 2003 en la Fundación Santa Fe de Bogotá. RESULTADOS: Se encontró que el 69,2 por ciento de los pacientes eran hombres. Ocho pacientes fueron sintomáticos (61,5 por ciento). La edad promedio fue de 40,4 años. El síntoma predominante, en el grupo de pacientes sintomáticos debido a complicación del divertículo de Meckel, fue el dolor abdominal (50 por ciento) seguido por la hemorragia digestiva baja (33 por ciento). Ocho pacientes fueron sintomáticos; 6 de ellos con complicaciones asociadas al divertículo, siendo la más frecuente la obstrucción intestinal en un 50 por ciento de los casos. El tratamiento en un 53 por ciento de los casos fue la resección intestinal más anastomosis. Se encontró en cuatro de los 13 pacientes (30,7 por ciento) mucosa gástrica ectópica en el estudio histopatológico.CONCLUSIONES: El divertículo de Meckel es una patología, que aunque poco frecuente, debe considerarse en el diagnóstico diferencial en pacientes con dolor abdominal agudo y sangrado digestivo bajo. En la Fundación Santa Fe de Bogotá la presentación clínica del divertículo de Meckel es similar a la presentación clásica descrita en la literatura

Successful treatment of disseminated Aspergillosis in a leukemic child.

The incidence of severe fungal infections in the immunocompromised patient with malignancies has increased in recent years. This appears to be associated to the profound periods of immunosuppression and the extended use of broad spectrum antibiotics. Aspergillosis is the second most common fungal infection reported in the immunocompromised cancer patients. In patients with advanced immunosupression, the mortality due to invasive aspergillosis approaches 100% despite treatment with antifungal agents. Reports of complete or partial response to echinocandins are well demonstrated in adults, but very limited in the pediatric population. This report describes the case of a child with relapsed acute lymphoblastic leukemia (ALL) who developed cutaneous aspergillosis and subsequent multiorgan dissemination during therapeutic induction and was treated successfuly with caspofungin acetate.

Epstein-Barr virus in biopsies from patients with Hodgkin and non-Hodgkin lymphoma at the University of Puerto Rico immunohistochemistry laboratory.

OBJECTIVES: We aimed to determine the Epstein-Barr Virus (EBV) presence rate in our laboratory's lymphoma tissue biopsies for comparison with that reported in literature. BACKGROUND: The presence of EBV has been established in Hodgkin lymphoma (HL), endemic Burkitt Lymphoma and some non-Hodgkin lymphomas (NHL). It has been linked to geographic, ethnic and socioeconomic factors, with a lower rate in developed countries. METHODS: We used the immunoperoxidase technique to determine the rate of the EBV LMP-1 in eighty-seven biopsies diagnosed as lymphoma. Tissue slides were stained using the Ventana Automated Slide Stainer with the DAKO EBV LMP-1 primary antibody and the results were analyzed with the SYSTAT program. RESULTS: We found an LMP-1 positive rate of 50% for 22 cases of HL and 35% for 63 cases of NHL. Among HL, 5 were children and 16 were adults, with LMP-1 positive rates of 60% and 50% respectively. Among NHL, 3 were children and 59 were adults, with equal LMP-1 positive rates of 33%. The sex LMP-1 positive rates for HL were 42% for 12 males and 60% for 10 females. Among NHL, the sex LMP-1 positive rates were 39% for 38 males and 28% for 27 females. NHL was further subdivided into subtypes and LMP-1 primary antibody positive rates were reported. CONCLUSIONS: We found a similar presence rate of EBV in the HL biopsies to that of developed countries, but a similar presence rate of EBV in NHL biopsies to that of developing countries.

Metástasis osea de un meningioma angioblastico intracraneal: informe de un caso

Se reporta un caso de metástasis ósea múltiples de un meningioma angioblástico (hemangiopericitoma intracraneal). Desde el punto de vista clínico y patológico, es esencial tener presente que la variante angioblástica del meningioma tiene un mayor índice de recurrencia y metástasis que las otras formas de meningioma

Es necesario el examen microscópico del sedimento urinario en los análisis de rutina? / Is it necessary the microscopic examination of the urinary sediment in routine urinalysis?

Se evalúam 1,372 análisis de orina, comparando las pruebas químicas, incluyendo esterasas de leucocitos, con el examen microscópico del sedimento urinario y las consecuencias clínicas de no hacer el examen microscópico a las orinas con pruebas químicas normales. De las 1,372 pruebas, 545 tuvieron el análisis químico y el examen microscópico negativo, y 39 tuvieron pruebas químicas negativas y examen microscópico positivo. La sensitividad de las pruebas químicas para detectar alteraciones en el tracto urinario fue de 93% y la especificidad fue de 65%. El valor predictivo positivo fue de 63% y el valor predictivo negativo fue de 93%. Las alteraciones más frecuentes en el sedimiento que no se hubieran detectado con las pruebas químicas solamente fueron: bacterias, hongos y tricomonas químicas solamente fueron: bacterias, hongos y tricomonas, ahora bien no se demostró la utilidad del examen microscópico en estos pacientes. En base a estos datos, se recomienda hacer examen microscópico del sedimiento urinario sólo en aquellos casos de análisis de orina de rutina que presenten alguna ateración en las pruebas químicas