Accessory Thyroid Research Articles

Autonomously functioning nodule arising from accessory mediastinal thyroid tissue

Functional imaging using radionuclide Tc99m pertechnetate is routinely used in the evaluation of the problems related to the thyroid gland. Scintiscan has been useful in the visualization of thyroid tissue in ectopic sites due to congenital developmental anomalies. Similarly, the scan helps in establishing the diagnosis of autonomously functioning nodule when the nodule being evaluated appears “hot” with suppression of rest of the gland activity. Here, we present a very rare case of autonomously functioning thyroid adenoma in an ectopic focus of accessory thyroid tissue in the mediastinum.

HISTOLOGICAL STUDY OF THE THYROID AND PARATHYROID GLANDS IN IRAQI BUFFALO "BUBALUS BUBALIS" WITH REFERRING TO THE SEASONAL CHANGES

The present study included the collection of thyroid and parathyroid glands from the abattoirs of middle of Iraq in Summer and Winter seasons 2006-2007. The samples were fixed by 10% formalin and processed by the routine histological techniques, then stained by H and E, PAS and Van Gieson stain, then studied under light microscope. Dimensions were measured by ocular micrometer. Analysis of data was done by T-test. The most striking result declared that the thyroid gland showed no differences in histological characters between both seasons as the buffalo was poor thermoregulator animal. It is tempting to speculate that the thyroid gland provide an adaptive advantage for survival of the buffalo in the nature arid environment. The parafollicular cells (C-cells) were sparse and found singly in the thyroid glands. Flat dark nuclei of myoepithelial cells were recognized around the thyroid follicles. This study was referred to the presence of accessory thyroid gland which contains simple follicular epithelium, and little amount of the colloid. Our current study revealed the presence of internal and external parathyroids. The oxyphilic cells in the internal parathyroid gland were not observed. Note: this work in part of Master Science Thesis, submitted to the College of Veterinary Medicine, Baghdad University.

Case of an Ectopic Thyroid Gland at the Lateral Neck Masquerading as a Metastatic Papillary Thyroid Carcinoma

Ectopic thyroid glands generally occur in the midline as a result of abnormal median migration, and their presence lateral to the midline is rare. We present one case of an ectopic thyroid gland masquerading as a lateral neck metastasis of a papillary thyroid carcinoma (PTC). In this case of a 54-yr-old woman with left PTC, we suspected left lateral neck metastasis on preoperative neck computed tomography. The patient underwent total thyroidectomy, central compartment neck dissection, and left modified radical neck dissection (MRND). The patient was diagnosed as having an accessory thyroid gland on the lateral neck on the final pathologic report. Surgeons should be aware of the existence of an ectopic thyroid gland in unusual locations.

Unique variant of levator glandulae thyroideae muscle

Clinical AnatomyVolume 20, Issue 8 p. 966-967 Compendium of Anatomical Variants Unique variant of levator glandulae thyroideae muscle Jeremy K. Gregory, Corresponding Author Jeremy K. Gregory [email protected] Mayo Medical School, Mayo Clinic College of Medicine, Rochester, MinnesotaMayo Medical School, Mayo Clinic College of Medicine, 200 1st St. SW, Rochester, MN 55905Search for more papers by this authorDarlene M. Guse, Darlene M. Guse Mayo Medical School, Mayo Clinic College of Medicine, Rochester, MinnesotaSearch for more papers by this author Jeremy K. Gregory, Corresponding Author Jeremy K. Gregory [email protected] Mayo Medical School, Mayo Clinic College of Medicine, Rochester, MinnesotaMayo Medical School, Mayo Clinic College of Medicine, 200 1st St. SW, Rochester, MN 55905Search for more papers by this authorDarlene M. Guse, Darlene M. Guse Mayo Medical School, Mayo Clinic College of Medicine, Rochester, MinnesotaSearch for more papers by this author First published: 18 October 2007 https://doi.org/10.1002/ca.20522Citations: 6AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article.Citing Literature Volume20, Issue8November 2007Pages 966-967 RelatedInformation

The pyramidal lobe: clinical anatomy and its importance in thyroid surgery

The pyramidal lobe could be a source of pitfalls in thyroidectomy, due to its frequency but unreliable preoperative diagnosis on scintigraphic images. Special attention has to be paid to the pyramidal lobe to avoid leavings of residual tissue when complete removal of the thyroid is indicated. Sixty cadaveric specimens were examined with special emphasis to the topographical anatomy and expansion of the pyramidal lobe. A pyramidal lobe was found to be present in 55% of the cadavers (32/58). It was found more frequently in men than in women. In men the median length was 14 mm and in women 29 mm. An accessory thyroid gland was present in one specimen, in four cases the isthmus was missing. The pyramidal lobe branched off more frequently from the left part of the isthmus (16) than from the right (7) or the midline (9). In two cases it originated from the left lobe. Additionally 23 scintigraphic images were analyzed to evaluate the visualization of a pyramidal lobe. Only three of them showed enlargements of the isthmus that could be taken as a pyramidal lobe. Due to its frequency the pyramidal lobe should be regarded as a normal component of the thyroid. It is not reliably diagnosed by scintigraphic imaging because scintigraphy can only give functional information but not morphological one. Therefore the anterior cervical region has to be investigated very carefully during operation in order not to leave residual thyroid tissue in total thyroidectomy.

Branchial‐like cysts of the thyroid associated with solid cell nests

Presented herein is the case of a 65-year-old man with a 20 year history of thyroid hypofunction. On sonography a cystic lesion 4 x 4 x 5 cm in largest diameter was found, replacing most of the right lobe of the thyroid gland. Microscopically, the lesion was composed of labyrinth-like cystic structures (LCS) lined by a few layers of benign-appearing squamous cells and filled by mucinous material. Adjacent to the cyst walls were discontinuous patches of a lymphoid tissue, composed of haloed centrocyte-like cells or germinal centers mostly depleted of germinal cells. Additionally, there were numerous squamous cell nests equivalent to solid cell nests (SCN), all of which were surrounded by a similar-looking lymphoid tissue. Rare SCN were thus cystically changed and contained a small amount of mucus. The SCN communicated with the LCS: the former represented the most distal outpouchings of the latter. The epithelial structures were surrounded by a loose collagenous adipocytic stroma with plump fibroblasts, which resembled the stroma often seen in lateral neck cysts associated with structures such as cartilage, accessory salivary gland tissues, cysts and accessory thyroid and thymus. Immunohistochemically, all lesional elements were negative for calcitonin and thyroglobulin. The results of the paper suggest that branchial cleft-like cyst have an origin in the ultimobranchial body.

A case of œsophageal polypus accompanied by a tumour of an accessory thyroid gland

A case of œsophageal polypus accompanied by a tumour of an accessory thyroid gland

Anthropological variations in the anatomy of the human thyroid arteries.

Knowledge of anatomic variability of the superior (STA), inferior (ITA), and lowest accessory (IMA) thyroid arteries may be helpful in certain clinical conditions. However, details of this variability have not been thoroughly described. Specifically, whether the presence and site of origin of STA, ITA, and IMA are influenced by the anthropological group, to what extent their origin is symmetric or asymmetric, and the role played by this variability in visualizing each thyroid artery by nonselective thyroid angiography is not known. To clarify this we conducted a meta-analytical study on Caucasian and Asian subjects, the latter including only Japanese and Koreans. In Caucasians and Asians the presence of superior vessels compared to inferior vessels was more frequent and the probability of symmetric or asymmetric arterial origin for STA were equivalent. However, better recognition of inferior rather than superior vessels was achieved by nonselective angiography in Caucasians. Finally, different frequencies of presence and site of origin for each artery were identified in Caucasians compared to Asians. Our results suggest that the higher frequency of IMA in Asians than in Caucasians should result in a search for an IMA-dependent feeding artery of inferior parathyroid adenomas, primarily the mediastinal ones, especially in Asians both by imaging and transcatheter ablative approaches. In addition, we have found that a small percentage of Caucasian subjects lack an STA on the left side. Therefore, anatomic arterial compatibility should be carefully evaluated in the preoperative stage of laryngeal transplantation maintaining in situ the donor's thyroid by terminal anastomoses between donor and recipient STAs. Finally, the lack of any individual thyroid artery in either Caucasians or Asians might influence the distribution of autonomic supply that runs with thyroid vessels to the thyroid parenchyma. This appears functionally relevant in cases of traumatic or surgical lesions of the cervical sympathetic chain involving thyroid nerves. In fact, a restricted local autonomic control of thyroid activity might be related to individual rami of thyroid nerves.

ADENOMATOUS GOITER OF THE ACCESSORY THYROID GLAND WITH HYPERTHYROIDISM -REPORT OF A CASE-

A 62-year-old man was admitted to the hospital because of a lump in the neck. After admission, cervical CT, ultrasonography, scintiscan and blood examination revealed an adenoma of the right lobe of the thyroid with slight hyperthyroidism. At operation, we found two tumors and no connection was found between the tumors and the thyroid gland. Only tumor extirpation was performed. The gross pathological specimens were 50×40 mm and 25×27 mm in size. Histological findings revealed the adenomatous goiters of the two accessory thyroid glands. After the operation thyiroid function tests were within normal limits. So-called ectopic thyroid glands are classified into two groups whether the thyroid gland is in the right place or not. This case is very rare and is worth for reporting. We think that ectopic thyroid gland with normal thyroid gland should be called accessory thyroid gland.

Accessory Thyroid Tissue in the Right Ventricle

In an asymptomatic 66-year-old woman presenting a systolic murmur in the pulmonic area, echocardiography evidenced a voluminous mass in the right ventricular outflow tract resembling a cardiac tumor. Histologic finding was that of aberrant normal thyroid. Although the occurrence of ectopic thyroid tissue in the heart is rare, it should be considered in the differential diagnosis whenever a mass is located at the level of the interventricular septum and encroaches on the right ventricular outflow tract. In these cases, a thyroid scintiscan may avoid an unnecessary surgical intervention.

Circannual Rhythms in Gonads and Endocrine Organs of the Great Tit Parus major in South-West Sweden

Seasonal studies on gonads, accessory sex organs, adrenals and thyroid glands of adult Great Tits from a population in south-west Sweden showed that testes started to grow rapidly at the end of March and reached maximal size in the middle of April. Testicular regression started in the middle of July. The ovary reached maximal size at the end of April. The cycle of the Leydig cells could be related to annual changes in sexual behaviours. Notable was the complete absence of mature Leydig cells during August and September. Concomitant with a short period of increased sexual interactions in October the Leydig cells reappeared. There seemed to be a time lag in the response of the seminal vesicles to an increased testosterone production from the Leydig cells. Adrenal and thyroid glands, in both sexes, showed cyclic changes in their activity during the year. Maximal cortical activity, in both sexes, was found during the breeding period. The breeding and molting periods were associated with high thyroid activity in both sexes.

The accessory thyroid glands of the dog around the intrapericardial aorta.

The accessory thyroid glands distributed in the fatty tissues surrounding the ascending aorta of the dog were investigated by light and electron microscopy.1. Out of the 45 dogs examined, 29 possessed one or more accessory thyroid glands, in the most numerous case six (Table 1). They were generally oval in form and measured 1-2mm in long diameter.2. There was recognized not a single parafollicular cell in the accessory thyroids, although 26 glands were examined in serial sections and stained by silver impregnation, pseudoisocyanin and lead-hematoxylin known as the positive staining methods for the parafollicular cells. Otherwise, the light and electron microscopic structures of the accessory thyroids corresponded to those of the main thyroid glands.3. The reactions under the light and electron microscopes of the follicular cells of the accessory thyroid to hypophysectomy and treatment of antithyroid drug were identical with those of the main thyroids.4. After thyroidectomy, the accessory thyroids showed conspicuous hyperactivity. Although their morphological changes resembled those of the animals injected with antithyroid drug, they scarcely proliferated.5. In dogs with induced hypercalcemia the accessory thyroid glands were not affected at all.6. The present study indicates that the follicular cells and parafollicular cells were of distinct cell lines and that the accessory thyroid glands may be separated from the main thyroid before the latter incorporates the ultimobranchial body.

Accessory Thyroid Tissue in the Goat

SUMMARY Accessory thyroid tissue was present either at the base of the neck or between the rami of the jaws in four of 17 normal adult goats. Six-and-a-half months after three of these four goats had been thyroidectomized the accessory tissues had disappeared in two and their 131 I-concentrating capacity had diminished greatly in the other. Residual or accessory thyroid tissue was found at the site of the original thyroid gland or in other sites 12 to 14 months after operation in 13 of 16 goats thyro-parathyroidectomized as immature animals.

Observations on the ultimobranchial gland in small wild and laboratory mammals, with special reference to the histochemical localization of polysaccharides

AbstractThis is the last of a series of observations involved in a comparative histological study of the ultimobranchial body in vertebrates. Complete serial longitudinal or transverse paraffin sections were made of formol alcohol, Bouin's, and formalin‐fixed ultimobranchial and thyroid tissues that had been removed from adult specimens of the cat, cotton rat, ground squirrel, Guinea pig, kangaroo rat, bushytailed wood rat, rabbit, and raccoon. The alcian blue‐PAS, aldehyde fuchsin‐alcian blue, mucicarmine, alcian blue‐safranin, Best's carmine, and toluidine blue staining procedures show that the glandular mammalian ultimobranchial tissue is capable of producing considerable amounts of various mucosubstances, particularly the acid mucopolysaccharides, and other carbohydrate‐containing materials. The carbohydrate moiety has been histochemically identified as mucopolysaccharides possessing acidic groups, those having both carboxyl and ester sulfate groups; and as glycogen, muco‐and glycoproteins and other carbohydrate‐protein complexes. The differences in the intensity and localization of a given staining reaction reflect not only individual and species variations but also significant differences in the position of the ultimobranchial tissue in relation to the thyroid gland. An accessory thyroid lobule found near parathyroid IV and thymus IV in a bushy‐tailed wood rat may represent a cystic manifestation of the ultimobranchial body because its follicles varied greatly in size and were lined by a thick stratified squamous epithelium. The possible hormonal mechanisms (TSH, thyroxine) involved in the regulation of ultimobranchial activity are discussed in relation to the gland's production, storage, and release of mucopolysaccharides and other secretory substances.

Accessory thyroid in the lateral floor of the mouth: Report of a case, with embryologic considerations

The postmortem finding of an accessory thyroid in the lateral floor of the mouth of an 86-year-old woman is described. Embryology of the median and lateral thyroid anlage and lesions resulting from faulty embryogenesis of median and lateral thyroid analgen are discussed. The described accessory thyroid in the lateral floor of the mouth is explained by defective embryogenesis of one lateral thyroid anlage.

INNOCUOUS ACCESSORY THYROID NODULES.

THIS STUDY was prompted by the emphasis which has been placed on so-called lateral aberrant thyroid tumors during the last 30 years or so and the relatively little attention that has been called to the innocuous nodules of thyroid tissue in the immediate vicinity of the thyroid gland itself. Because of this and the failure to clearly distinguish between the two entities, a good deal of confusion has arisen. Goss5states, Small detached portions of thyroid tissue are sometimes found in the vicinity of the lateral lobes or above the isthmus; they are called accessory thyroid glands (glandulae thyreoideae accessoriae). Warren and Meissner15state, Aberrant thyroid tissue is sometimes found adjacent to the thyroid gland, particularly near the midline. Such aberrant thyroid tissue occurs in small nodules and shows a histologic structure similar to that of the main body of the thyroid. Pathologists are quite familiar with the

Effects of Estradiol and Dehydroepiandrosterone on the Reproductive Cycle of the Cow. II. Histology of Primary and Accessory Reproductive Organs, Pituitary, Thyroid, and Adrenal Glands

Summary Histological examination of ovarian follicles from three heifers receiving daily injections of 250 to 350µg of estradiol for varying lengths of time revealed an abnormal or absent granulosa layer and a thickening and partial luteinization of the thecal layers. In one heifer injected daily with 3.5mg estradiol for 30 days prior to slaughter, all follicles larger than 1mm in diameter exhibited follicular atresia; no follicle exceeded 10mm in size. The percentage of granular small beta cells from the basophilic zone of the anterior pituitary was increased in the heifers receiving at least 350µg of estradiol daily. Cystic corpora lutea were present on the ovaries of three out of four animals injected daily with 20 to 80mg of dehydroepiandrosterone (DHA). The percentage of hyalinized small beta cells from the basophilic core of the anterior pituitary was increased with daily injections of at least 40mg of DHA. Epithelial cell heights of the thyroid, oviduct, cervix, uterine superficial and basal glands were greater in the animals treated with estradiol than in the animals treated with DHA. The differences in height were not significant (P

Thyroid Grafts

During the fifth week of gestation, the thyroglossal anlage arises from the ventral wall of the primitive pharynx at the foramen cecum and migrates caudally. The thyroid gland arises from proliferation of the cells at the distal end of this diverticulum. The thyroglossal duct usually disappears, but if it persists it may become enveloped in the developing hyoid bone. During this same period of development, the ultimobranchial bodies arise from the fourth branchial arch. They migrate laterally around the neck to fuse with the developing thyroid gland. This is all that is known about the ultimobranchial bodies. There is no evidence that they are actually thyrogenic. An aberrant thyroid gland is the development in an abnormal site of the body's total thyroid tissue. An accessory thyroid gland is a supplementary fraction of thyroid tissue that grows at a distance from a normally placed gland. Aberrant or accessory thyroid glands may

ON THE DEVELOPMENTAL POTENCY OF PRESUMPTIVE MATERIAL OF THE THYRO-GLOSSAL DUCT

It is well known that accessory thyroid bodies in the human body can frequently be observed, in the course of development, between foramen caecum linguae and the isthmus or the pyramidal lobe of the thyroid, that is, in the thyro-glossal duct. This suggests that under a certain condition, thyroid tissue will differentiate from entodermal material comprising the thyro-glossal duct, and it can be presumed that this duct has prospective potency to differentiate the thyroid tissue. In Bufo vulgaris formosus in the latter neurula stage, presumtive material of primordial thyroid gland is found in the foregut underlying the protuberance of the primordial sucker-organ, and is surrounded by the entdermal material, which makes up the thyro-glossal duct, on both external and cephalic side. Now the entodrmal area was removed in such a way as to leave about half of the presumptive material of primordial thyroid, participating in the formation of the thyroglossal duct, to test for the developmental potency of the remaining part. As controls, larvae of total ablation and intact ones were used.It was found that in the control group of total ablation, metamorphosis was perfectly inhibited, while in the group of partial ablation it took place though remarkably delayed as compared with the normal control. Microscopical observation of the experimental group revealed that the thyroid tissue was formed heterotopically in different amounts according to the individual larva, but that all showed some deficiency as compared with the normal thyroid. It was thus clarified that material of the thyro-glossal duct possesses the potency to regulate thyroid formation in the case of partial ablation of the primordial thyroid. The thyroid tissue was situated in all the experimental cases between the root of the tongue and pericardium, but did not show lobulation, being composed of only one lobe. The mesenchymal capsule was richly vasculated, and the epithelial cells scarcely different from those of the normal thyroid, but follicle formation was imperfect in many cases. In the follicular space was observed a large amount of colloid with secrete granules. The other abnormalities were detarded formation of the tongue, and the formation of ectodermal epithelial cystes in area adjacent to the thyroid tissue.

The surgical treatment of retrotracheal intrathoracic goiter.

Numerous surgical procedures have been suggested for the proper management of thyroid masses which migrate into or occur ectopically in areas removed from their usual anatomical location in front of the trachea. It is generally accepted that subclavicular and substernal extensions of moderate size are easily and properly delivered through the conventional cervical incision. Unusually large masses, if soft, can be reduced in size before delivery by the morcellation technique of Lahey. 1 Substernal extensions, however, which have migrated far inferiorly or are too solid to allow intracapsular gouging are best removed by using a combined cervical and median sternotomy approach. 2 That thyroid tumors can occur ectopically is suggested by authentic reports of intratracheal, aortic, pericardial, and intracardiac accessory thyroid masses.* Some of these ectopic tumors have been encountered deep in the thorax above the diaphragm or in the posterior mediastinum behind the esophagus far removed from the cervical