Signo de  rueda de carreta en los nódulos tiroídeos: ¿Sinónimo de benignidad? The  spoke wheel sign in thyroid nodules: synonym of benignity?

La patología nodular tiroidea es altamente prevalente. La mayoría de los nódulos son asintomáticos y solo identificados en imágenes. Hemos establecido la relación entre una morfología especial del nódulo en  rueda de carreta e histología benigna. Se realizó una revisión de la base de datos de nódulos puncionados bajo US y estudiados histológicamente entre 2003 y 2011. Criterios de selección: nódulos mixtos/sólidos, redondos/ovales, rodeados por un halo, presentando estructuras convergentes hacia un punto central con o sin calcificaciones y vasos periféricos con otros orientados hacia el centro del nódulo. De 3.204 nódulos puncionados 79 (2,5%) presentaron el signo. Tamaño promedio: 28,3 mm. Cincuenta y ocho resultaron nódulos coloideos benignos en PAAF. El resto fueron informados como lesiones foliculares (4 operados benignos, 7 en seguimiento y estables, 10 sin información). Este signo es poco frecuente, pero puede ser un elemento más que colabore en la discriminación ecográfica de benignidad/malignidad, especialmente en nódulos tiroideos de gran tamaño.Thyroid nodular disease is a highly prevalent condition. Most nodules are asymptomatic and only identifiable on images. We have established a relationship between the particular  spoke wheel pattern of thyroid masses and a benign histology. A review of our institutional database of thyroid punctured under ultrasound guidance, histologically studied between 2003 and 2011, was performed. Node selection criteria included: mixed /solid, round /oval, surrounded by a halo, with radial structures converging toward a central point, with or without calcifications, and with peripheral vessels along with others oriented toward the center of the thyroid masses. Seventy-nine (2.5%) out of 3.204 punctured masses exhibited this sign. Average size: 28.3 mm. Fifty-eight masses were benign colloid nodules as diagnosed on FNA biopsy. Remaining masses corresponded to Lesion Follicular (4 benign, surgically treated; 7 under follow-up, stable; 10 with no information). Despite being a rare radiologic finding, the  spoke wheel sign may be another element contributing to ultrasonographic discrimination between benignity and malignancy, especially in large thyroid masses

Past and present distribution, densities and movements of blue whales Balaenoptera musculus in the Southern Hemisphere and northern Indian Ocean

1. Blue whale locations in the Southern Hemisphere and northern Indian Ocean were obtained from catches (303 239), sightings (4383 records of 8058 whales), strandings (103), Discovery marks (2191) and recoveries (95), and acoustic recordings. 2. Sighting surveys included 7 480 450 km of effort plus 14 676 days with unmeasured effort. Groups usually consisted of solitary whales (65.2%) or pairs (24.6%); larger feeding aggregations of unassociated individuals were only rarely observed. Sighting rates (groups per 1000 km from many platform types) varied by four orders of magnitude and were lowest in the waters of Brazil, South Africa, the eastern tropical Pacific, Antarctica and South Georgia; higher in the Subantarctic and Peru; and highest around Indonesia, Sri Lanka, Chile, southern Australia and south of Madagascar. 3. Blue whales avoid the oligotrophic central gyres of the Indian, Pacific and Atlantic Oceans, but are more common where phytoplankton densities are high, and where there are dynamic oceanographic processes like upwelling and frontal meandering. 4. Compared with historical catches, the Antarctic ("true") subspecies is exceedingly rare and usually concentrated closer to the summer pack ice. In summer they are found throughout the Antarctic; in winter they migrate to southern Africa (although recent sightings there are rare) and to other northerly locations (based on acoustics), although some overwinter in the Antarctic. 5. Pygmy blue whales are found around the Indian Ocean and from southern Australia to New Zealand. At least four groupings are evident: northern Indian Ocean, from Madagascar to the Subantarctic, Indonesia to western and southern Australia, and from New Zealand northwards to the equator. Sighting rates are typically much higher than for Antarctic bluewhales