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

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 percent) 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.

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 por ciento) 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.

¿Existen nódulos coloidos tiroideos que no requieren punción diagnóstica? / Are there any colloid thyroid nodules which do not require diagnostic punctures?

Depending on age, sex, and geographic area, 19 to 67% of the general population is found to have thyroid nodules when submitted to ultrasonica-lly-guided diagnostic puncture. Being benign in more than a 80%, most of them corresponds to colloid nodules. Indiscriminate fine-needle aspiration not only increases health costs but also generates anxiety in patients. The echographic-histological correlation of thyroid nodules made it possible to define five typical patterns (colloid patterns 1, 2, 3; neoplastic type, and malignant pattern). Thirty three percent of colloid nodules may appear as follicular neoplasms or malign nodules, being puncture the only means for recognizing and establishing the difference between them. Nevertheless, 67% of nodules presents a typical appearance that corresponds to colloid patterns 1, 2, and 3, which show a weak association to cancer risk(0%, 0% and 1,5%, respectively). On this basis, ultrasound follow-up is advised to recognize them in order to significantly diminish unnecessary diagnostic histological punctures.

En el 19 al 67%> de la población general se diagnostican nodulos tiroideos mediante ultra-sonografía, dependiendo de la edad, sexo y área geográfica. En más del 80% su naturaleza es benigna y la gran mayoría corresponde a nodulos coloideos. Su punción indiscriminada aumenta costos y genera ansiedad. La correlación ultrasonográfica-histológica de los nodulos tiroideos permitió definir cinco patrones característicos (patrón coloideo típico tipos 1 a 3, patrón neoplásico y patrón maligno). El 33%> de los nodulos coloideos simula la apariencia de nodulos de tipo neoplasia folicular o de aspecto maligno y sólo con punción se puede diferenciar entre ellos. No obstante, el 67%> de los nodulos tiene aspecto típico y corresponden a patrones coloideos Tipo 1, 2 y 3, con una baja asociación con cáncer (0%, 0%y 1,5% en los tres grupos respectivamente), lo que autoriza su seguimiento ultrasonográfico. Al reconocerlos como tal, se puede disminuir en forma significativa las punciones diagnósticas innecesarias.

Detección y caracterización por ultrasonido de cuerpos extraños de partes blandas / Detection and characterization of soft tissue foreign bodies by ultrasonography

Background: Soft tissue foreign bodies are a frequent cause of consultation in emergency rooms. It is difficult to verify their existence since conventional radiology only detects radio opaque objects. Ultrasound can be a useful diagnostic procedure. Aim: To report our experience in the detection of soft tissue foreign bodies by ultrasound examination. Patients and methods: The ultrasonographic appearance of vegetables, glass and plastic, metal, bone and stones was studied in gelatin preparations. In a second stage, 52 patients (27 male, aged 3 to 88 years old) were studied, in whom the presence of a soft tissue foreign body was confirmed surgically. Results: The mean error of the procedure for the assessment of foreign body size was 0.2 mm in vitro and 0.5 mm in vivo. The deepness and involved planes were correctly diagnosed in 96 percent, the number of fragments were diagnosed correctly in 94 percent of cases. The type of foreign body was identified correctly in 77 percent of cases and complications were detected in 100 percent of cases. Conclusions: Ultrasound is a sensitive and accurate method for the detection of soft tissue foreign bodies