Separate thyrothymic thyroid remnant; clinically crucial anatomic variation

PURPOSE: The anatomical variations of the thyroid gland including separate thyroidal remnant at the thyrothymic area are of significance during thyroid surgery for “total” thyroidectomy, and for recurrent goitre. In the present study, we aimed to detect the separate rests of thyroidal tissue in the thyrothymic region.METHODS: The thyrothymic region was explored for identification, dissection, and excision of separate thyroidal remnants in 134 patients who underwent primary thyroid surgery. In this series, we studied the incidence and anatomical features of the thyrothymic remnant and its relation with other embryologic remnants.RESULTS: Overall, 222 sides of the thyroid were explored in this study. An entirely separate thyrothymic remnant of the thyroid was identified and excised in 8 of 134 patients (6%). Mean size of removed remnants was 36.4 mm (range, 29–45 mm) in diameter. The incidences of pyramidal lobe (PL) and Zuckerkandl's tubercle (ZT) were 71.6% and 59.7%, respectively. The thyrothymic remnant coexisted with PLs in 4 patients. Four patients had all 3 embryologic remnants: thyrothymic remnant, PLs, and ZTs.CONCLUSION: An entirely separate thyroidal remnant at the thyrothymic area is not a rare variation. The considerably large size of a remnant may threaten the completeness of thyroidectomy and may result in recurrence if it is left behind after thyroid surgery. Awareness, identification, and excision of the separate remnant at the thyrothymic area and the other embryologic remnants are critical for ensuring completeness of thyroidectomy and preventing recurrences.

Morphology of thyroid gland- a comparative study between male and female thyroid glands

Introduction: Thyroid gland surgery is one of the most common surgical interventions in the head and neckregion. The gland is located low down in front of the neck. It consists of two symmetrical lobes united by anisthmus. A small portion of the gland substance often projects upwards from the isthmus, generally to the left ofthe midline as the Pyramidal lobe (PL). The Levator glandulae thyroidea(LGT) descends from the hyoid body to theisthmus or apex of Pyramidal lobe, innervated by branch of external laryngeal nerve. Hence this study onmorphological analysis of the gland will hopefully help to minimise the complications during the surgeries.Materials and methods: The study was done in 50 specimens which included glands dissected out of adultcadavers, specimens used for teaching in the department and rest of them were collected from fresh cadavericworkshops.statistical analysis was done between male and female thyroid glands using spss software 20version, dependant variables were compared using chi square test.Result: The shape of the gland was mostly normal, Isthmus was related to 2,3,4 th tracheal rings and in 6% casesit was absent. The pyramidal lobe was seen mostly to the left in 38% cases, LGT was absent in 36% cases,muscular LGT was seen on left side in 18% cases and STA was seen related to the medial border of apex in 52%cases.Conclusion: In the present study we observed variation in the morphology between the male and female thyroidglands

A Study Of The Variations In The Morphology Of The Thyroid Gland And Its Surgical Correlations

Introduction: Being a highly vascular and one of the essential endocrine glands, the knowledge of the variationsin the morphology of the thyroid gland stands an important role with respect to their identification, isolation orpreservation, and prevention of any untoward complication during the surgeries around the neck region, thusincreasing the chances of favourable surgical outcome.Aim: The aim of the present study was to identify the frequent variants in the structure of the thyroid gland, andto compare the same with the work of other authors.Materials and Methods: The present study was conducted on total 86 thyroid glands with morphological variations,out of which 42 were of males and 44 were of females. These were obtained during routine dissection of the neckin the adult human cadavers aged above 50 years.Results: The most common variation in the present study was the presence of pyramidal lobe (50% in males and65.9% in females), followed by the levator glandulae thyroidae (45.2% in males and 52.3% in females), absenceof the isthmus (7.1% in males and 20.5% in females), accessory thyroid tissue (2.4% in males and 2.8% infemales), and the least common was presence of groove in the thyroid tissue (0% in males and 2.8% in females).There were also combination of variants in some thyroids.Conclusion: The study emphasizes on the common anatomical variations in the thyroid gland morphology andtheir surgical correlations.

Morphological Variations of the Thyroid Gland in the North Indians: A Cadaveric Study with its Clinical Relevance

Introduction: The morphological variations of the thyroid gland are not an uncommon phenomenon and may due to embryological remnant or non-specific development of different parts of it. Prior anatomical knowledge of these variations is of immense importance to prevent catastrophies during or after thyroid surgeries. Therefore, in this study we aimed to investigate the prevalence of morphological variations of the thyroid glands in north Indian cadavers. Subjects and Methods: This study was conducted on 50 formalin embalmed adult human cadavers aging between 40–65 years, of which 40 were males and 10 were females. Thyroid glands were dissected and examined properly for the presence of pyramidal lobe, levator glandulae thyroidae, accessory thyroid tissue and complete absence of isthmus. Results: The pyramidal lobe was present in 9 (18%) and frequently arising from the right side of the isthmus. LGT was found in 7 (14%) and almost in all cases it was extending from the apex of the pyramidal lobe to the hyoid bone. Only 2 (4%) cadavers did not show an isthmus while accessory thyroid tissue was found only in one case. Morphological variations were more common in females than in males and the difference was statistically significant (p value<0.05). The means of all measured parameters were higher in female than in male but these gender differences were not significant (p>0.05). Conclusion: Morphological variation of the thyroid gland is a common phenomenon, particularly in female. Hence it requires proper detection and documentation prior to any thyroid surgery, so that iatrogenic catastrophies can be avoided

Anatomical variations of thyroid glands in northeastern-Thai embalmed cadavers / Variaciones anatómicas de la glándula tiroides en cadáveres embalsamados del noreste de Tailandia

SUMMARY: This study aimed to investigate the variation patterns of thyroid glands in embalmed cadavers donated for anatomical studying and research in the northeastern part of Thailand. The crossed-sectional descriptive study was applied to systemically observe the thyroid gland in abnormality of 45 embalmed cadavers. The study was conducted in the Anatomy Laboratory of College of Medicine and Public Health, Ubon Ratchathani University. The indications of thyroid gland abnormalities were recorded by photographs before classification of data used further in a descriptive analysis using SPSS. The results showed that 8 of the 45 cadavers (17.8 %) were observed with thyroid gland abnormality (4 males; 8.9 % and 4 females; 8.9 %). Such variations could be classified into 3 types; pyramidal lobe (8.8 %), levator glandulae thyroideae (2.2 %) and the co-existing of levator glandulae thyroideae (8.8 %), respectively. The thyroid gland abnormality observed in this study was mainly related to many previous reports. Besides the number of thyroid variations are a crucial indication of thyroid gland abnormality recurring, these gland abnormalities are susceptible to the operation of radiology physicians in thyroidectomy and tracheostomy.

RESUMEN: El objetivo de este estudio fue investigar los patrones de variación de la glándula tiroides en cadáveres embalsamados donados para estudios e investigaciones anatómicas en el noreste de Tailandia. El estudio transversal descriptivo se aplicó para observar sistémicamente la glándula tiroides en caso de anomalía en 45 cadáveres embalsamados. El estudio se realizó en el Laboratorio de Anatomía de la Facultad de Medicina y Salud Pública de la Universidad de Ubon Ratchathani. Las anomalías de la glándula tiroides se registraron mediante fotografías antes de la clasificación de los datos y se utilizaron en un análisis descriptivo con SPSS. Los resultados mostraron que en 8 de los 45 cadáveres (17,8 %) se observaron anomalías de la glándula tiroides (4 hombres; 8,9 % y 4 mujeres; 8,9 %). Tales variaciones podrían ser clasificadas en 3 tipos: lóbulo piramidal (8,8 %), músculo elevador de la glándula tiroides (2,2 %) y la coexistencia del músculo elevador de la glándula tiroides (8,8 %), respectivamente. La anomalía de la glándula tiroides observada en este estudio se relacionó principalmente con informes anteriores. Además, la cantidad de variaciones tiroideas es una indicación crucial de la anomalía de la glándula tiroides que se repite, esta anomalía de la glándula es susceptible a las intervenciones de los médicos radiólogos en la tiroidectomía y la traqueotomía.

Morphometric Study Of Pyramidal Lobe And Levator Glandulae Thyroidae And Its Surgical Significance

Introduction: The thyroid gland is an important endocrine gland in human body , thyroid disorder being thecommon health problem affecting almost 5% of the population. Incomplete removal of thyroid gland may causerecurrence of disease and it could be dangerous when complete removal of gland tissue is indicated in Grave’sdisease or malignant carcinoma . Remains of pyramidal lobe ,the cause. Hence its necessary to know the trueincidence of anatomic variants of thyroid viz , pyramidal lobe or levator glandulae thyroidae to perform safeand effective surgery.Aims: To study the morphological variations of lobes of thyroid gland . viz. pyramidal lobe, levator glandulaethyroidae and its incidence in western maharashtra population.Materials and methods: The study was conducted on total of 60 thyroid glands(male-34, female-26) collectedduring routine dissection from adult cadavers of both sexes aged more than 18 yrs in the department of anatomy,B. J. government medical college , Pune. A cross sectional descriptive type of study was performed.Results: Pyramidal lobe was found in 25% cases , more common in females (30.76%), than males (20.58%) .Levator glandulae thyroidae was seen in (38.33%) cases, more common in females (38.46%) than males (38.23%). Pyramidal lobe was mostly originated from center of isthmus (46.6%) and least from right end of isthmus(6.66%) . In pyramidal lobe, length and breadth were more in males whereas thickness was more in females.Maximum 73.9% LGT seen were muscular in texture followed by fibromuscular , fibrous respectively. Maximumnumber of LGT seen were extending from pyramidal lobe to hyoid bone (43.47%), followed by either lobe ofthyroid gland to hyoid bone . All dimentions of LGT were more in males. PL associated with LGT was seen in23.33% cases , males 20.59% and females 26.92% , thus showing female preponderance.Conclusion: The study highlights the incidence of pyramidal lobe and levator glandulae thyroidae which isimportant to keep in mind for successful thyroid surgeries to prevent recurrence of diseases .

Anatomical variations and developmental anomalies of the thyroid gland in Ethiopian population: a cadaveric study / 대한해부학회지

Because of its embryonic origin, the thyroid gland is predisposed to multiple anatomical variations and developmental anomalies. These include the pyramidal lobe, the origin of levator glandular thyroidae, the absence of the isthmus, ectopic thyroid, accessory thyroid tissues, etc. These anatomical variations are clinically significant to surgeons, anatomists, and researchers. The present study was designed to report anatomical variations and developmental anomalies of the thyroid gland in Ethiopian population. The study was conducted on 40 cadavers used for routine dissection classes. The thyroid gland was exposed and observed for any variations and developmental anomalies. The length, width, and thickness of the lobes were measured using a vernier caliper. Differences in the incidence of pyramidal lobe and absence of the isthmus between sexes were tested using a Pearson chi-square test. The mean length, width, and thickness of the right lobe were 4.24 cm, 1.8 cm, and 1.6 cm, respectively, whereas it was 4.08 cm, 1.8 cm, and 1.6 cm, respectively for that of the left lobe. The pyramidal lobe was noted in 52.5% of the cadavers. The levator glandulae thyroidae were prevalent in 40% of the cadavers. The isthmus mainly overlies the 2nd to 4th tracheal rings and was absent in 7.5% of the cadavers. Accessory thyroid tissue and double pyramidal lobes were noted in 2.5% of the cadavers. Most of the variations of the thyroid gland were seen frequently in female but it was not statically significant. Different clinically important and rare variations of the thyroid gland were found.

Multiple Morphological Variations in the Thyroid Gland: Report of two Cases.

The variety of multiple morphological variations in the thyroid gland is found as a result of disturbed organogenesis in humans as agenesis, hypoplasia, accessory, ectopy and hemiagenesis. In the routine undergraduate dissection of the thyroid gland, multiple anomalies of the thyroid gland were encountered in 50 and 60 years old female and male cadaver respectively. These were in form of absent isthmus with accessory thyroid lobe in between two lateral lobes, pyramidal lobe arising from left lobe of thyroid with levator glandulae thyroidae in first case. Second case showed narrow isthmus related to first tracheal ring and levator glandulae thyroidae arising from left lobe. In these case studies, we highlight various developmental anomalies of the thyroid gland as absent isthmus, pyramidal lobe and accessory lobe with levator glandulae thyroidae. Hence a thorough knowledge of such morphological variations of thyroid gland helps the surgeons in better planning of safe, effective and uncomplicated operative procedures in resection of thyroid and tracheotomy procedures.

Variantes anatómicas del lóbulo piramidal del tiroides / Anatomical variants of the thyroidal pyramidal lobe

Introducción: el lóbulo piramidal del tiroides es considerado una malformación congénita sobre la cual los conocimientos acumulados son escasos y muy limitados; provenientes, en su mayoría, de estudios en cadáveres e imaginológicos. El objetivo de la investigación fue determinar las características morfométricas del lóbulo piramidal del tiroides en pacientes intervenidos quirúrgicamente. Materiales y Métodos: se realizó un estudio observacional, descriptivo de carácter prospectivo con cohorte histórica en un universo de 116 pacientes, mayores de 16 años, intervenidos quirúrgicamente por alguna afección, no deformante, de la glándula tiroides en el Hospital Provincial Universitario Celia Sánchez Manduley, en Manzanillo, Granma. La vía de abordaje quirúrgico empleada fue la cervicotomía horizontal de Kocher. En el curso de la cervicotomía se observó el lóbulo piramidal del tiroides; midiéndose de manera extracorpórea el lóbulo después de la resección practicada. Resultados: el lóbulo piramidal del tiroides se presentó en 77 pacientes (66,38 %), su unión a la glándula fue más frecuente en el lóbulo izquierdo (49,35 %) siendo la forma cónica la más observada (31,17 %). La longitud media fue de 4,01 cm ± 2,01. Conclusiones: el lóbulo piramidal del tiroides es una malformación congénita del esbozo medial y laterales del tiroides presente en más de la mitad de los individuos, frecuentemente de forma cónica, unida a la porción izquierda de la glándula tiroides con una longitud media de 4,01 cm.

Background: the thyroidal pyramidal lobe is considered a congenital malformation on which the accumulated knowledge is scarce and very limited, coming mainly from researches in corpses and image studies. The aim of the current research was determining the morphometric characteristics of the thyroidal pyramidal lobe in surgically treated patients. Materials and methods: a descriptive, observational, prospective research with historical cohort was carried out in a universe of 116 patients, aged more than 16 years, who were surgically treated due to any no deforming condition of the thyroidal gland in the Teaching Provincial Hospital “Celia Sanchez Manduley”, in Manzanillo, Granma. The used way of surgical access was the Kocher´s horizontal cervicotomy. In the cervicotomy course, the thyroidal pyramidal lobe was observed and the lobe was extracorporeally measured after the reception was practiced. Outcomes: thyroidal pyramidal lobe was present in 77 patients (66,38 %); its link with the gland was more frequent in the left lobe (49,35 %) being the conical form the most observed one (31,17 %). The average length was 4,01 ± 2,01 cm. Conclusions: the thyroidal pyramidal lobe is a congenital malformation of the thyroidal medial and lateral outline that is present in more than half of the individuals, frequently having conical form, linked to the thyroidal gland left portion with an average length of 4,01 cm.

Morphological variations of the thyroid gland.

Background: The knowledge of various morphological & developmental anomalies of thyroid gland will help the surgeons in better planning of safe & effective surgery. Considering these facts we studied the variations of thyroid gland. Methods: The material for the present study was collected from the department of forensic medicine, MMC & RI, Mysore, which includes 56 male and 33 female adult postmortem cadavers aged between 18 to 80 years. A dissection was carried out to expose thyroid glands & variations were observed in the morphology of thyroid gland. Results: 1) 9% of specimens had agenesis of isthmus. 2) 46% of specimens had pyramidal lobe. 3) 41% of specimens had levator glanduli thyroidae. 4) 2.24 % of specimens had accessory thyroid tissue. Conclusion: This study highlights the various morphological anomalies of the thyroid gland which forms cornerstone to safe & effective surgery.

Comparison between Ultrasonography and Computed Tomography for Detecting the Pyramidal Lobe of the Thyroid Gland: A Prospective Multicenter Study

OBJECTIVE: To compare the detection rates of the pyramidal lobe of the thyroid gland (TPL) using ultrasonography (US) and computed tomography (CT) in a prospective multi-center study. MATERIALS AND METHODS: We enrolled 582 patients who underwent neck CT at six institutions. Each radiologist prospectively evaluated the presence and features of TPLs on thyroid US. Radiologists were divided into two groups according to their previous experience in detecting TPL on US or CT. The same radiologist also retrospectively assessed CT findings, blinded to the corresponding US findings. RESULTS: The pyramidal lobe of the thyroid glands were detected in 230 cases (39.5%) on US and in 276 cases (47.6%) on CT. The TPL detection rate at the six institutions ranged from 22.0% to 59% for US and from 34.1% to 59% using CT. There were significant differences between US and CT in the detection rate, length, anteroposterior diameter, volume, and superior extent of TPL (p < or = 0.027). The TPL detection rates on both US and CT (p < 0.001) differed significantly according to the experience level of the radiologists. When the CT result was used as a reference standard, the sensitivity, specificity, positive and negative predictive values, as well as the accuracy of US for TPL detection were 72.6%, 91.5%, 89.3%, 77.3%, and 82.1%, respectively. CONCLUSION: Our prospective multicenter study revealed that US could detect TPL with relatively high diagnostic accuracy compared to CT. Because the detection rate of TPL varied significantly according to the radiologists' level of experience, careful inspection is necessary to avoid imaging pitfalls and ensure appropriate evaluation of TPL on both US and CT.

Agenesis of Isthmus of thyroid gland with presence of pyramidal lobe and levator glandulae thyroideae.

A wide range of morphological and developmental variations of thyroid gland like hypoplasia, ectopic thyroid tissue, hemiagenesis or agenesis of thyroid gland has been reported. Out of these agenesis of the thyroid isthmus is a very rare congenital anomaly. Thyroid isthmus agenesis does not manifest clinical symptoms, and it can be confused with other thyroid pathologies. Also the presence of levator glandulae thyroideae and its anatomical variations gain importance in the pathologies which are related to thyroid gland and their treatment modalities. We hereby, report the absence of isthmus and presence of levator glandulae thyroideae and pyramidal lobe in a middle aged male cadaver. The present case report is an attempt to highlight the implications of variation of thyroid gland from diagnostic, phylogenetic and functional perspectives.

Papillary thyroid microcarcinoma in a thyroid pyramidal lobe

We report an extremely rare case of papillary thyroid microcarcinoma (PTMC) in the thyroid Epub ahead of print pyramidal lobe (TPL). A 48-year-old woman underwent ultrasound-guided fine-needle aspiration for a small thyroid nodule in the right lobe in local clinic, and it revealed a malignant cytology. On preoperative ultrasonography for tumor staging in our hospital, another small suspiciously malignant hypoechoic nodule was detected in the left TPL. Total thyroidectomy and central nodal dissection were performed. Histopathology confirmed PTMCs in the left TPL and both thyroid lobes. Ultrasonography for TPL should be required for complete evaluation of possible multifocality of thyroid malignancy.

Papillary Carcinoma Arising from the Pyramidal Lobe of the Thyroid

The authors present a rare case of papillary carcinoma arising from the pyramidal lobe of the thyroid in a 54-year-old woman, who presented with a right submental palpable mass. An ultrasound evaluation depicted a 3 cm mixed echoic mass from the thyroid cartilage level without a focal lesion in the thyroid gland. Surgical specimens obtained during bilateral thyroidectomy confirmed papillary carcinoma of the pyramidal lobe. To the authors' knowledge, this is the first case report to describe papillary carcinoma arising from the pyramidal lobe of the thyroid gland.

Morphologic Variations of the Thyroid Gland in Korean Adults / 체질인류학회지

The shape of the thyroid gland was similarly described in many anatomical text books, but we observed that the shape of the thyroid gland was very diverse in the dissecting room. This study was performed to clarify the morphologic characteristics of the thyroid gland in Koreans. One hundred sixty eight Korean adult cadavers were used for this study. It was 57.1% that the size and the location of both lobes were symmetric. The frequency of the existence of the Pyramidal lobe was 76.8%. The pyramidal lobe located in the left, right, and middle of the isthmus were 48.8%, 26.4%, and 21.7% respectively. And the pyramidal lobes located in the both sides of the isthmus were 3.1% of the cases. The thyroid gland was classified into six types. Type I in which the thyroid gland had the classical H shape and the relatively wide isthmus was observed in 31.5%. Type II in which the thyroid isthmus could be distinguished but the distance between two lobes was very short was found in 28.0%. In type III, the inferior margins of the isthmus and the lateral lobes made a straight line (29.2%). In type IV, two lateral lobes of the thyroid gland were directly fused and the isthmus was not distinguished (5.4%). In type V, the thyroid gland had no isthmus and the lateral lobes were separated (3.0%). Type VI was not belonged to five types because of its irregular shape (3.0%). The incidence of the classical thyroid gland described in the text books was 12.5% in Korean adults.