Valor de la correlación de lesiones sospechosas de tiroides diagnosticadas por punción aspirativa con aguja fina guiada por ecografía con el diagnóstico histopatológico final de las piezas quirúrgicas

En estos últimos años la Punción Aspirativa con Aguja Fina ( PAAF) bajo control ecográfico en la patología de la tiroides se ha transformado en la principal herramienta diagnóstica en la evaluación inicial de todo nódulo tiroideo. Comenzó a implementarse en los 80, con gran variabilidad en la terminología diagnóstica. Con el fin de unificar las diferentes categorías en los diagnósticos citológicos, se consensuó la clasificación de Bethesda (año 2007) que reconoce 6: benigna, atipía con significado incierto (indeterminado), neoplasia folicular, sospechosa, maligna e insatisfactorio. Tanto en la categoría de indeterminado como en la sospechosa donde el riesgo de malignidad es alto, se sugiere el examen histológico de la tiroides (mediante lobectomía o tiroidectomía total) para llegar a una diagnóstico de certeza.Facultad de Ciencias Médica

Evidence of human occupation in Mexico around the Last Glacial Maximum.

The initial colonization of the Americas remains a highly debated topic1, and the exact timing of the first arrivals is unknown. The earliest archaeological record of Mexico-which holds a key geographical position in the Americas-is poorly known and understudied. Historically, the region has remained on the periphery of research focused on the first American populations2. However, recent investigations provide reliable evidence of a human presence in the northwest region of Mexico3,4, the Chiapas Highlands5, Central Mexico6 and the Caribbean coast7-9 during the Late Pleistocene and Early Holocene epochs. Here we present results of recent excavations at Chiquihuite Cave-a high-altitude site in central-northern Mexico-that corroborate previous findings in the Americas10-17of cultural evidence that dates to the Last Glacial Maximum (26,500-19,000 years ago)18, and which push back dates for human dispersal to the region possibly as early as 33,000-31,000 years ago. The site yielded about 1,900 stone artefacts within a 3-m-deep stratified sequence, revealing a previously unknown lithic industry that underwent only minor changes over millennia. More than 50 radiocarbon and luminescence dates provide chronological control, and genetic, palaeoenvironmental and chemical data document the changing environments in which the occupants lived. Our results provide new evidence for the antiquity of humans in the Americas, illustrate the cultural diversity of the earliest dispersal groups (which predate those of the Clovis culture) and open new directions of research

Indications and Efficacy of Gamma Knife Stereotactic Radiosurgery for Recurrent Glioblastoma: 2 Decades of Institutional Experience

BACKGROUND: The role of stereotactic radiosurgery (SRS) for recurrent glioblastoma and the radionecrosis risk in this setting remain unclear. OBJECTIVE: To perform a large retrospective study to help inform proper indications, efficacy, and anticipated complications of SRS for recurrent glioblastoma. METHODS: We retrospectively analyzed patients who underwent Gamma Knife SRS between 1991 and 2013. We used the partitioning deletion/substitution/addition algorithm to identify potential predictor covariate cut points and Kaplan-Meier and proportional hazards modeling to identify factors associated with post-SRS and postdiagnosis survival. RESULTS: One hundred seventy-four glioblastoma patients (median age, 54.1 years) underwent SRS a median of 8.7 months after initial diagnosis. Seventy-five percent had 1 treatment target (range, 1-6), and median target volume and prescriptions were 7.0 cm(3) (range, 0.3-39.0 cm(3)) and 16.0 Gy (range, 10-22 Gy), respectively. Median overall survival was 10.6 months after SRS and 19.1 months after diagnosis. Kaplan-Meier and multivariable modeling revealed that younger age at SRS, higher prescription dose, and longer interval between original surgery and SRS are significantly associated with improved post-SRS survival. Forty-six patients (26%) underwent salvage craniotomy after SRS, with 63% showing radionecrosis or mixed tumor/necrosis vs 35% showing purely recurrent tumor. The necrosis/mixed group had lower mean isodose prescription compared with the tumor group (16.2 vs 17.8 Gy; P = .003) and larger mean treatment volume (10.0 vs 5.4 cm(3); P = .009). CONCLUSION: Gamma Knife may benefit a subset of focally recurrent patients, particularly those who are younger with smaller recurrences. Higher prescriptions are associated with improved post-SRS survival and do not seem to have greater risk of symptomatic treatment effect