Microcalcificaciones y focos ecogénicos puntiformes, ¿qué tan bien sabemos lo que estamos viendo? / Microcalcifications and punctate echogenic foci, how well do we know what we are seeing?

Resumen: La presencia de microcalcificaciones en nódulos tiroideos es un signo muy específico de malignidad, al corresponder a cuerpos de Psammoma. No existen suficientes estudios que demuestren una correlación entre su presencia histológica y su aspecto ecográfico real. Materiales y Métodos: Se seleccionaron todos los nódulos con tamaño mayor a 3 cm puncionados en el Hospital Clínico Universidad Católica entre los años 2010-2015 y se clasificó el aspecto ecográfico según la presencia de 3 tipos de focos ecogénicos con una definición más estricta a lo usual. Se correlacionó lo anterior con hallazgos en biopsias. Resultados: 44 nódulos correspondieron a cáncer papilar de tiroides. Hubo relación estadísticamente significativa entre una nueva definición ecográfica de las microcalcificaciones (focos ecogénicos puntiformes) y la presencia histológica de cuerpos de psamomma. Discusión: Habría una buena correlación entre una definición más estricta y la presencia real de microcalcificaciones en histología, mejorando la alta tasa de sobrediagnóstico advertido recientemente por algunos autores.

Abstract: The presence of microcalcifications in thyroid nodules is a very specific sign of malignancy, as it corresponds to Psammoma bodies. There are not enough studies that demonstrate a correlation between their histological presence and their actual ultrasound appearance. Materials and Methods: All nodules larger than 3 cm punctured at the Universidad Católica Clinical Hospital between 2010-2015 were selected, and the sonographic appearance was classified according to the presence of 3 types of echogenic foci according to a stricter definition than usual. The above was correlated with findings in biopsies. Results: 44 nodules corresponded to papillary thyroid cancer. There was a statistically significant relationship between a new ultrasound definition of the microcalcifications (punctate echogenic foci) and the histological presence of psamomma bodies. Discussion: There would be a good correlation between a stricter definition and the actual presence of microcalcifications in histology, improving the high rate of over diagnosis recently noticed by some authors.

Histogenesis of Developing Human Thyroid.

In human beings the thyroid gland is one of the largest of the endocrine organs. It is one of the earliest endocrine organs to be differentiated and has an important hormonal role in embryonic development. The importance of thyroid gland is to promote growth and development of the brain during fetal life and for the first few years of post-natal life[1, 2]. The purposes of present study are 1)to study the microscopic structure of the human thyroid in different gestational age groups of normal stillborn foetuses; 2) to correlate the size of thyroid follicles; the nature and amount of colloid content of thyroid follicles at different stages of development. The study was carried out on 50 stillborn normal human foetuses. The microscopic structure of thyroid was studied under light microscope. The study concluded the developmental staging of thyroid as: the precolloid stage; the colloid formation stage; the folliculogenesis stage; secretory activity stage.

Thyroid hemiagenesis: case report and review of literature

Thyroid hemiagenesis is a rare embryological condition in which the left lobe is usually absent. The remaining thyroid lobe may present as benign adenoma, multinodular goiter, hyperthyroidism, chronic thyroiditis, hypothyroidism and rarely carcinoma. The most common pathology involved in thyroid hemiagenesis is hyperthyroidism. This report probably represents the first ever reported case of thyroid hemiagenesis from Kuwait. This 56-year-old Kuwaiti male presented with a left thyroid swelling, a history of progressive fatigue, constipation and weight gain, and exercise intolerance. The patient's preoperative workup included an ultrasound scan, thyroid scan, computed tomography [CT] scan and thyroid profile. His T4 was 3 pmol/ 1 and TSH was 200 uUI/ml. All investigations revealed a multinodular goiter in the left lobe with an absent right lobe. A fine-needle aspiration biopsy was suspicious for malignancy. The patient underwent left thyroid lobectomy. The operative findings confirmed hemiagenesis of the right lobe and histopathology showed benign multinodular goiter in the left lobe. The parathyroids on the left side were in the normal position. This case report presents a rare case of hypothyroidism and absent right thyroid lobe. It may help increase awareness of this rare anomaly of the thyroid gland and thus make preoperative diagnosis possible

Effect of maternal sodium Fluoride administration during gestation and lactation on the thyroid gland development of albino rat offspring

The study was carried to follow up the postnatal developmental sequences of the rat thyroid gland in addition to investigate the effect of gestational and lactational administration of sodium fluoride on the offspring thyroid gland and its reversibility after fluoride withdrawal. Thirty mature female albino rats were used and allowed for mating. Then the known pregnant rats were divided into two groups: group [A] [control group] received daily distilled water and group [B] [experimental group] received daily oral dose of sodium fluoride dissolved in distilled wafer via gastric tube [40mg/kgm body weight]. Drug administration started from the gestational day 14 up to the weaning on the postnatal day 21. The offspring of the control and experimental [fluoride treated] groups were used at the age of one, five, ten fifteen days.three weeks, one and six months [eight pups from each age]. The thyroid glands were dissected out and then the thyroid specimens were processed for histological study using Hemtoxylin and Eosin and Van Gieson 's staining methods. Histomorphometric technique was done to estimate the volume proportion of the thyroid follicles and interstitial tissues as well as the thickness of follicular epithelium of the rats of the experimental [fluoride treated] group compared to that of the control group at the age of three weeks, one and six months using the point counting technique. The obtained results were statistically analyzed using student t test. The histological results highlighted the normal postnatal developmental events of rat thyroid gland. The thyroid gland showed a primitive and immature microfollicular pattern at birth to attain the macrofollicular pattern by the second postnatal week. Further functional maturation was observed by the third postnatal week till they reached full maturity by the first postnatal month. These observations demonstrated well defined mature macrofollicles that contain abundant colloid material with visible absorptive vesicles. The histological findings of the current study demonstrated the effect of sodium fluoride on thyroid follicular pattern, follicular colloid content and the interfollicular connective tissue. These observations included predominance of microfollicular pattern, presence of disturbed follicular pattern reduction of colloid content [glycoprotein], widening of the interfollicular spaces, increased vascularity as well as obvious fibroplastic and monocytic infiltration. The histomorphometric measurements revealed statistically significant changes behween rats of the control and experimental groups at the age of three weeks and one month. The histological and histomorphometric results of the rats of the experimental group at the age of six months remained more or less similar to that of the control apart from widening of the interfollicular space. This partial recovery of thyroid histopathological and histomorphometric indices after cessation of sodium fluoride administration could indicate reversibility of its adverse effect

Accessary thyriod nodule in sub-mandibular region

A case of an accessory thyroid nodule with a diagnosis of focal lymphocytic thyroiditis, in 23 years old lady, on histopathological examination, is presented. Patient had a single swelling in the left submandibular region without any abnormality. Postoperative thyroid scan showed thyroid gland in its normal anatomical location with suppressed activity and thyroid profile revealed subclinical hypothyroidism

Toxic response of endosulfan to breeding and non-breeding female mosquitofish.

To investigate if toxic effects by endosulfan, a commonly used insecticide, are dependent on the breeding condition of an organism, both breeding and non-breeding female western mosquitofish, Gambusia affinis, were exposed to 0.1, 0.5, 1 ppb of endosulfan. After a 5-week exposure period, we examined physical factors such as ovary weight and anal fin length in fish of both reproductive conditions and the size of thyroid follicles in non-breeders. Breeding female fish exposed to endosulfan did not show any significant changes in physical factors, but non-breeding females exposed to endosulfan had a significantly greater ratio of anal fin/ body length and larger thyroid follicles than did control females. These results demonstrate that the response to exposure to environmental contaminants may be dependent upon seasonal reproductive condition.

Aumento de volumen de la glandula tiroides en mujeres embarazadas de la ciudad de La Paz: signo de deficiencia moderada de yodo / Increase thyroid volume in pregnact women in the city of La Paz: a sign of moderate iodine deficiency

Evaluar el aumento de volumen de la glándula tiroides durante el embarazo como signo de desorden de deficiencia de yodo (DDI) relacionada a una disminución del cntenido de yodo en la sal. Diseño y método. Se determinó el volumen tiroideo por ecografía utilizando la fórmula de Brunn en un grupo de mujeres embarazadas y un grupo control en el Hospital de la Mujer de la Ciudad de La Paz. Resultados. Se encontro un aumento significativo del volumen tiroideo en mueres embarazadas frente al grupo control (19.8+-12mL vs. 10+-5.3mL p=0.0048). Conclusión. El trabajo demuestra que existe incremento significativo del volumen tiroideo en mujeres embarazadas relacionado con un grado moderado de deficiencia de yodo.

Altered maternal thyroid function: fetal and neonatal development of rat.

Influence of maternal thyroid status on fetal and neonatal development of rats has been studied. Maternal hypothyroidism resulted impaired reproduction and intrauterine growth retardation of offsprings as revealed by their reduced body weight, heart weight, body length and tail length. Offsprings born to hypothyroid mothers showed very high rate of mortality and none of them survived beyond eight days. Maternal hyperthyroidism did not cause any abnormality on reproduction. Hyperthyroid mothers showed increased rate in body weight gain during pregnancy which was associated with increased weight of body and heart of fetuses born to hyperthyroid mothers. Plasma thyroxine was not measurable in fetus from hypothyroid mothers till 21st day of gestation. The results of the present study showed that maternal thyroid status plays an important role in fetal and neonatal growth and development.

Influence of sympathetic denervation of the thyroid by superior cervical ganglionectomy on the growth processes in the gland in basal conditions and after hemithyroidectomy

The aim of the present study has been to examine the effects of superior cervical ganglionectomy (SCGx) on the hypertrophic (thyroid lobe weight) and hyperplastic (thyroid mitotic activity) response of the rat thyroid gland in basal conditions or after hemithyroidectomy (hemiTx), both being assessed 14 days after the surgeries. It has been shown that: 1) Ipsilateral and./or bilateral SCGx brought about the growth (both hypertrophy and hyperplasia) of thyroid lobes in the animals with intact thyroid; the strongest hypertrophic reaction occurred after ipsilateral SCGx and the strongest hyperplastic response followed bilateral SCGx. 2) Unilateral SCGx, when performed ipsilaterally to the remaining thyroid lobe after hemiTx amplified the hypertrophic, but no hyperplastic response of this lobe. Both contralateral and bilateral SCGx had no effect on the hypertrophy of the remaining thyroid lobe. Unexpectedly, both bilateral and contralateral SCGx exerted the suppressive effect on the hyperplastic response of the thyroid lobe following hemiTx. These results indicate that the sympathetic innervation plays an important role in the control of thyroid growth of intact animals and/or after hemiTx