Romboencefalitis por Listeria monocytogenes: Patología emergente en relación al brote epidémico. Presentación de tres casos clínicos / Listeria monocytogenes rhomboencephalitis: Report of three cases

An unusual number of cases of rhomb encephalitis have occurred in Chile because of the increased frequency of infections caused by Listeria monocytogenes. We report three females aged 36, 40 and 55 years, with the disease. All presented with a prodrome characterized by headache, nausea, vomiting and fever, followed by ataxia and unilateral palsies of the third, seventh and twelfth cranial nerves. One patient presented also a hemi-hypoesthesia. Magnetic resonance showed lesions in the posterior aspect of the brain stem, specifically in relation to the floor of the fourth ventricle. Blood cultures were positive for Listeria monocytogenes.

Metástasis cerebral de un carcinoma hepatocelular fibrolamelar: reporte de un caso y revisión de la literatura / Brain metastasis of a fibrolamellar hepatocellular carcinoma: case report and literature review

El carcinoma hepatocelular fibrolamelar(CHF) es un tumor hepático maligno, poco frecuente, con características clínicas, histológicas e imagenológicas que lo diferencian del carcinoma hepatocelular. Se le consideraba de mejor pronóstico que el hepatocarcinoma, sin embargo, estudios recientes han demostrado altas tasas de recidivas y metástasis. Presentamos el caso clínico de un paciente con diagnóstico de CHF, el que evoluciona con desarrollo de metástasis cerebral, sin reportes similares en la literatura.

Fibrolamellar hepatocellular carcinoma (FHC) is an infrequent liver tumor with clinical, histological and radiological features that makes it distinguishable from hepatocellular carcinoma. It has been considered to have a better prognosis compared to hepatocarcinoma, but recent studies have shown a worst outcome than initially assumed, with a high rate of relapse and metastasis. We present a case of FHC that developed brain metastases, which has not been previously described in the literature.

Utilidad clínica de la fusión SPECT/CT con marcadores externos en patología oncológica / Fusion of SPECT with computed tomography or magnetic resonance for the interpretation of abnormal tracer uptake

Background: Interpretation of abnormal foci with high tracer uptake may require morphological correlation. Fusion of functional images obtained by single photon emission computed tomography (SPECT) and anatomical images obtained by computed tomography (CT) or magnetic resonance (RM) allows an integrated comprehension of complementary information. Aim To demonstrate that SPECT/CT fusion with external markers is useful in clinical practice to clarify the location and pathological meaning of questionable foci. Material and methods: Thirty four pairs of images from separate equipments (31 SPECT/CT and 3 SPECT/RM) pertaining to 29 patients, were fused. Fifty one foci of abnormal tracer uptake of uncertain pathological meaning were analyzed. These were classified before and after the fusion as probably malignant or probably benign. Results: Seventy percent of patients had a differentiated thyroid carcinoma. The fusion localized 100 percent of foci. Nine percent had a normal and 26 percent an abnormal anatomy. Before fusion 82 percent of foci were classified as potentially malignant. This figure changed to 59 percent after the fusion (p <0.01). Therefore the suspicion of malignancy was presumptively confirmed in 72 percent of foci and fusion results would have reached a 27 percent of incremental diagnostic value in 14 cases that changed of category (11 with differentiated thyroid carcinoma, one with colorectal cancer, one with a nasalEwingsarcoma and one with a brain tumor). Conclusions: The fusion of SPECT and CT is useful in selected patients, specially those with differentiated thyroid carcinoma. The fusion of SPECT and RM is also feasible.

Encefalomielitis aguda diseminada de presentación atípica: utilidad de la biopsia estereotáctica para su diagnóstico. Caso clínico / Diagnosis of acute disseminated encephalomyelitis using a stereotaxic biopsy: Report of one case

We report a 15 year-old female presenting with behavioral disturbances, headache, left hemiparesis and paresis of the vertical gaze. CAT scan and magnetic resonance showed an involvement of right thalamus, third ventricle and medial temporal lobe suggesting an encephalitis or lymphoma. 201Thalium SPECT suggested a lymphoma. A stereotaxic biopsy showed a subacute demyelinizing lesion, compatible with an acute disseminated encephalomyelitis. The patient was treated with Methylprednisolone with resolution of symptoms. She remains in good condition after one year of follow-up.

Otosclerosis: análisis imagenológico con tomografia computada multicorte / Otosclerosis: imaging analysis with multislice helical computed tomography

Actualmente con los equipos de tomografía computada multicorte (TCM) podemos obtener cortes submilimétricos, los que nos permiten obtener un mejor detalle de la anatomía. Esto ha sido particularmente útil en el estudio del oído. Esta capacidad nos permite además detectar alteraciones que antes no eran posibles de observar. El estudio de la otosclerosis es un ejemplo de ello: con los equipos actualmente logramos evidenciar alteraciones en los estudios de imagen en etapas tempranas de esta enfermedad. El objetivo de esta revisión es dar a conocer la utilidad de la tomografía computada multicorte en el estudio de la otosclerosis y las alteraciones que determina en los estudios imagenológicos.

At the present, new brain multislice helical CT allows axial slices of less than one milimiter, improving therefore imaging anatomy resolution. Ear imaging has been one of the most improved. This technology has been showing new details of pathologic conditions not detected before. Otosclerosis in one of them detecting with the new equipment early signs of thisdisease. The purposse of this article is to demostrate the capability of multislice helical CT in studying otosclerosis and the characteristical imaging findings.

Errores neurorradiológicos frecuentes en TC y RM / Frequent neuroradiological misinterpretations in CT and MR

Se presenta una revisión de las variantes anatómicas normales más frecuentes de ver en cráneo, cerebro y espacios de líquido cefalorraquídeo, que pueden ser malinterpretradas como hallazgos patológicos llevando a la realización de estudios más complejos e innecesarios. En la mayoría de los ejemplos, las variantes anatómicas son solo visibles en TC y en otros casos son exclusivas de RM. El propósito de esta revisión es conocer las variantes más frecuentemente observadas en imágenes de RM y TC con el fin de obtener un diagnóstico acertado evitando la realización de estudios posteriores innecesarios que solo llevan a aumentar los costos en salud de nuestros pacientes.

Corea inducido por el uso de anticonceptivos orales en dos casos / Chorea induced by oral contraceptives in 2 cases

We report two women using oral contraceptives, aged 17 and 33 years old, who presented with hemichorea. In both patients all other possible causes of chorea were discarded and the disease disappeared when contraceptives were discontinued. Four months later, the 33 years old patient used again oral contraceptives and chorea reappeared. This rare complication of contraceptive use has been previously reported in young and mainly nulliparous women